From 1223fb1ef579013ba0594062b51635a35b3aee8c Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Mon, 1 Mar 2021 23:42:11 -0500
Subject: [PATCH 01/22] Rename 'Expanding' to 'Expanded'

---
 dev/Expander/Expander.cpp             |  6 +++---
 dev/Expander/Expander.h               |  2 +-
 dev/Expander/Expander.idl             |  4 ++--
 dev/Generated/Expander.properties.cpp | 10 +++++-----
 dev/Generated/Expander.properties.h   |  6 +++---
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/dev/Expander/Expander.cpp b/dev/Expander/Expander.cpp
index a2f22bf3cd..1546aeb7db 100644
--- a/dev/Expander/Expander.cpp
+++ b/dev/Expander/Expander.cpp
@@ -91,9 +91,9 @@ void Expander::OnContentSizeChanged(const winrt::IInspectable&, const winrt::Siz
 }
 
 
-void Expander::RaiseExpandingEvent(const winrt::Expander& container)
+void Expander::RaiseExpandedEvent(const winrt::Expander& container)
 {
-    m_expandingEventSource(*this, nullptr);
+    m_expandedEventSource(*this, nullptr);
 }
 
 void Expander::RaiseCollapsedEvent(const winrt::Expander& container)
@@ -105,7 +105,7 @@ void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChange
 {
     if (IsExpanded())
     {
-        RaiseExpandingEvent(*this);
+        RaiseExpandedEvent(*this);
     }
     else
     {
diff --git a/dev/Expander/Expander.h b/dev/Expander/Expander.h
index 01879908c4..efc374f2af 100644
--- a/dev/Expander/Expander.h
+++ b/dev/Expander/Expander.h
@@ -26,7 +26,7 @@ class Expander :
     void OnApplyTemplate();
 
 
-    void RaiseExpandingEvent(const winrt::Expander& container);
+    void RaiseExpandedEvent(const winrt::Expander& container);
     void RaiseCollapsedEvent(const winrt::Expander& container);
 
     void OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& args);
diff --git a/dev/Expander/Expander.idl b/dev/Expander/Expander.idl
index 04744fbbec..c1b57e6a97 100644
--- a/dev/Expander/Expander.idl
+++ b/dev/Expander/Expander.idl
@@ -27,7 +27,7 @@ unsealed runtimeclass Expander : Windows.UI.Xaml.Controls.ContentControl
     [MUX_PROPERTY_CHANGED_CALLBACK(TRUE)]
     ExpandDirection ExpandDirection{ get; set; };
 
-    event Windows.Foundation.TypedEventHandler<Expander, ExpanderExpandingEventArgs> Expanding;
+    event Windows.Foundation.TypedEventHandler<Expander, ExpanderExpandedEventArgs> Expanded;
     event Windows.Foundation.TypedEventHandler<Expander, ExpanderCollapsedEventArgs> Collapsed;
 
     [MUX_PROPERTY_NEEDS_DP_FIELD]
@@ -52,7 +52,7 @@ enum ExpandDirection
 [MUX_PUBLIC]
 [default_interface]
 [webhosthidden]
-runtimeclass ExpanderExpandingEventArgs
+runtimeclass ExpanderExpandedEventArgs
 {
 }
 
diff --git a/dev/Generated/Expander.properties.cpp b/dev/Generated/Expander.properties.cpp
index db76982530..4ad32a5b4c 100644
--- a/dev/Generated/Expander.properties.cpp
+++ b/dev/Generated/Expander.properties.cpp
@@ -22,7 +22,7 @@ GlobalDependencyProperty ExpanderProperties::s_TemplateSettingsProperty{ nullptr
 
 ExpanderProperties::ExpanderProperties()
     : m_collapsedEventSource{static_cast<Expander*>(this)}
-    , m_expandingEventSource{static_cast<Expander*>(this)}
+    , m_expandedEventSource{static_cast<Expander*>(this)}
 {
     EnsureProperties();
 }
@@ -211,12 +211,12 @@ void ExpanderProperties::Collapsed(winrt::event_token const& token)
     m_collapsedEventSource.remove(token);
 }
 
-winrt::event_token ExpanderProperties::Expanding(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs> const& value)
+winrt::event_token ExpanderProperties::Expanded(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs> const& value)
 {
-    return m_expandingEventSource.add(value);
+    return m_expandedEventSource.add(value);
 }
 
-void ExpanderProperties::Expanding(winrt::event_token const& token)
+void ExpanderProperties::Expanded(winrt::event_token const& token)
 {
-    m_expandingEventSource.remove(token);
+    m_expandedEventSource.remove(token);
 }
diff --git a/dev/Generated/Expander.properties.h b/dev/Generated/Expander.properties.h
index 70534be0e3..b28adb4e5f 100644
--- a/dev/Generated/Expander.properties.h
+++ b/dev/Generated/Expander.properties.h
@@ -43,11 +43,11 @@ class ExpanderProperties
 
     winrt::event_token Collapsed(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderCollapsedEventArgs> const& value);
     void Collapsed(winrt::event_token const& token);
-    winrt::event_token Expanding(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs> const& value);
-    void Expanding(winrt::event_token const& token);
+    winrt::event_token Expanded(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs> const& value);
+    void Expanded(winrt::event_token const& token);
 
     event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderCollapsedEventArgs>> m_collapsedEventSource;
-    event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs>> m_expandingEventSource;
+    event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs>> m_expandedEventSource;
 
     static void EnsureProperties();
     static void ClearProperties();

From 363c732069c5c2f050a2a7a58c59671e0611b12d Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Mon, 1 Mar 2021 23:42:32 -0500
Subject: [PATCH 02/22] Ensure Expanded/Collapsed fire after state is applied

---
 dev/Expander/Expander.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dev/Expander/Expander.cpp b/dev/Expander/Expander.cpp
index 1546aeb7db..2facc11aad 100644
--- a/dev/Expander/Expander.cpp
+++ b/dev/Expander/Expander.cpp
@@ -103,6 +103,8 @@ void Expander::RaiseCollapsedEvent(const winrt::Expander& container)
 
 void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)
 {
+    UpdateExpandState(true);
+
     if (IsExpanded())
     {
         RaiseExpandedEvent(*this);
@@ -111,7 +113,6 @@ void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChange
     {
         RaiseCollapsedEvent(*this);
     }
-    UpdateExpandState(true);
 }
 
 void Expander::OnExpandDirectionPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)

From 17c6d857bb5c89e8b00df88619848b34d9ec1481 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 00:26:07 -0500
Subject: [PATCH 03/22] Remove MaxWidth set in the default style

---
 dev/Expander/Expander.xaml            |  9 ++++-----
 dev/Expander/TestUI/ExpanderPage.xaml | 15 ++++++++++++---
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 6d52bf384c..50bc6700c7 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -23,14 +23,13 @@
         <Setter Property="Background" Value="{ThemeResource ExpanderBackground}" />
         <contract7Present:Setter Property="BackgroundSizing" Value="InnerBorderEdge" />
         <Setter Property="MinWidth" Value="{ThemeResource FlyoutThemeMinWidth}" />
-        <Setter Property="MaxWidth" Value="{ThemeResource FlyoutThemeMaxWidth}" />
         <Setter Property="MinHeight" Value="{StaticResource ExpanderMinHeight}" />
         <Setter Property="BorderThickness" Value="{ThemeResource ExpanderBorderThickness}" />
         <Setter Property="BorderBrush" Value="{ThemeResource ExpanderBorderBrush}" />
         <Setter Property="Padding" Value="{StaticResource ExpanderHeaderPadding}" />
-        <Setter Property="HorizontalAlignment" Value="Stretch" />
-        <Setter Property="HorizontalContentAlignment" Value="Left" />
-        <Setter Property="VerticalContentAlignment" Value="Center" />
+        <Setter Property="HorizontalAlignment" Value="Left" />
+        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
+        <Setter Property="VerticalContentAlignment" Value="Stretch" />
         <contract7Present:Setter Property="CornerRadius" Value="{ThemeResource ControlCornerRadius}" />
         <Setter Property="Template">
             <Setter.Value>
@@ -147,7 +146,7 @@
                         <!-- The clip is a composition clip applied in code -->
                         <Border x:Name="ExpanderContentClip" Grid.Row="1">
                             <Border
-                                x:Name="ExpanderContent"                         
+                                x:Name="ExpanderContent"
                                 Visibility="Collapsed"
                                 Background="{ThemeResource ExpanderDropDownBackground}"
                                 contract7Present:BackgroundSizing="{TemplateBinding BackgroundSizing}"
diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index 8b909bedd3..a20d0d7ebc 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -10,7 +10,7 @@
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d">
 
-    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+    <ScrollViewer Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
 
         <StackPanel Orientation="Vertical" HorizontalAlignment="Left">
             <StackPanel.ChildrenTransitions>
@@ -29,7 +29,7 @@
                 <Button AutomationProperties.AutomationId="ExpandedExpanderContent">Content</Button>
             </controls:Expander>
 
-            <controls:Expander AutomationProperties.AutomationId="CollapsedExpander" AutomationProperties.Name="Expander2" IsExpanded="False" Margin="12">
+            <controls:Expander AutomationProperties.AutomationId="CollapsedExpander" AutomationProperties.Name="Expander2" IsExpanded="False" Margin="12" MaxWidth="{ThemeResource FlyoutThemeMaxWidth}">
                 <controls:Expander.Header>
                     <TextBlock Text="This expander is collapsed by default. This is a long title to test the header width. ext should be wrapping here." TextWrapping="Wrap" Margin="0,12,0,13"/>
                 </controls:Expander.Header>
@@ -73,7 +73,16 @@
                     </StackPanel>
                 </controls:Expander>
             </local:TestControl>
+
+            <controls:Expander AutomationProperties.Name="ExpanderStretched" ExpandDirection="Down" IsExpanded="True" Margin="12" HorizontalAlignment="Stretch">
+                <controls:Expander.Header>
+                    <TextBlock Margin="0,0,0,1">This expander stretches along with its content</TextBlock>
+                </controls:Expander.Header>
+                <StackPanel HorizontalAlignment="Right">
+                    <TextBlock TextAlignment="Right">Content</TextBlock>
+                </StackPanel>
+            </controls:Expander>
         </StackPanel>
 
-    </Grid>
+    </ScrollViewer>
 </local:TestPage>

From 1f80b685225517a0a8ca6096b8f177875b165fcf Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 00:40:03 -0500
Subject: [PATCH 04/22] Make the expander properly size to content

The header and content container elements should always be stretched to give child controls maximum available area.
---
 dev/Expander/Expander.xaml            | 4 +++-
 dev/Expander/TestUI/ExpanderPage.xaml | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 50bc6700c7..2e605d2e6d 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -141,7 +141,7 @@
                             Content="{TemplateBinding Header}"
                             ContentTemplate="{TemplateBinding HeaderTemplate}"
                             ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
-                            HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
+                            HorizontalAlignment="Stretch"
                             IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" />
                         <!-- The clip is a composition clip applied in code -->
                         <Border x:Name="ExpanderContentClip" Grid.Row="1">
@@ -156,6 +156,8 @@
                                 MinHeight="{TemplateBinding MinHeight}"
                                 MinWidth="{TemplateBinding MinWidth}"
                                 MaxWidth="{TemplateBinding MaxWidth}"
+                                HorizontalAlignment="Stretch"
+                                VerticalAlignment="Stretch"
                                 Padding="{StaticResource ExpanderContentPadding}">
                                 <ContentPresenter
                                     Content="{TemplateBinding Content}"
diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index a20d0d7ebc..3d89b58e65 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -36,12 +36,12 @@
                 <TextBlock AutomationProperties.AutomationId="CollapsedExpanderContent">Content</TextBlock>
             </controls:Expander>
 
-            <controls:Expander AutomationProperties.Name="ExpanderWithButtons" IsExpanded="False" Margin="12">
+            <controls:Expander AutomationProperties.Name="ExpanderWithButtons" IsExpanded="False" Margin="12" MaxWidth="{ThemeResource FlyoutThemeMaxWidth}">
                 <controls:Expander.Header>
                     <ToggleButton>This is a toggle button in the header</ToggleButton>
                 </controls:Expander.Header>
                 <StackPanel>
-                    <TextBlock TextWrapping="Wrap">Content. This is long content to test wrapping on the content section, this content should be wrapping.</TextBlock>
+                    <TextBlock TextWrapping="Wrap">Content. This is long content to test wrapping on the content section, this content should be wrapping after the control expands to max width.</TextBlock>
                 </StackPanel>
             </controls:Expander>
 

From 66bf68f22a665b1236e606ba6f62c28d8d13a198 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 14:52:08 -0500
Subject: [PATCH 05/22] Remove Stretch content alignment (use Center default)

This aligns with the default Button style
---
 dev/Expander/Expander.xaml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 2e605d2e6d..d76ab0eb06 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -28,8 +28,6 @@
         <Setter Property="BorderBrush" Value="{ThemeResource ExpanderBorderBrush}" />
         <Setter Property="Padding" Value="{StaticResource ExpanderHeaderPadding}" />
         <Setter Property="HorizontalAlignment" Value="Left" />
-        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
-        <Setter Property="VerticalContentAlignment" Value="Stretch" />
         <contract7Present:Setter Property="CornerRadius" Value="{ThemeResource ControlCornerRadius}" />
         <Setter Property="Template">
             <Setter.Value>

From 0ad7bc5ddcaac645480aa70450b0dfa61060a633 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 14:52:24 -0500
Subject: [PATCH 06/22] Add Center VerticalAlignment

This aligns with the default Button style
---
 dev/Expander/Expander.xaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index d76ab0eb06..420d2e12d8 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -28,6 +28,7 @@
         <Setter Property="BorderBrush" Value="{ThemeResource ExpanderBorderBrush}" />
         <Setter Property="Padding" Value="{StaticResource ExpanderHeaderPadding}" />
         <Setter Property="HorizontalAlignment" Value="Left" />
+        <Setter Property="VerticalAlignment" Value="Center" />
         <contract7Present:Setter Property="CornerRadius" Value="{ThemeResource ControlCornerRadius}" />
         <Setter Property="Template">
             <Setter.Value>

From ee209e1e311bb13d55e293eb06d2f9976bc72a18 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 15:01:13 -0500
Subject: [PATCH 07/22] Remove Min/MaxWidth from intermediate controls

These should follow the layout root (parent grid) sizing.
---
 dev/Expander/Expander.xaml | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 420d2e12d8..cc87459277 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -131,8 +131,6 @@
                             BorderBrush="{TemplateBinding BorderBrush}"
                             BorderThickness="{TemplateBinding BorderThickness}"
                             MinHeight="{TemplateBinding MinHeight}"
-                            MinWidth="{TemplateBinding MinWidth}"
-                            MaxWidth="{TemplateBinding MaxWidth}"
                             contract7Present:CornerRadius="{TemplateBinding CornerRadius}"
                             IsEnabled="{TemplateBinding IsEnabled}"
                             Padding="{TemplateBinding Padding}"
@@ -153,8 +151,6 @@
                                 BorderBrush="{ThemeResource ExpanderDropDownBorderBrush}"
                                 BorderThickness="{StaticResource ExpanderDropdownDownBorderThickness}"
                                 MinHeight="{TemplateBinding MinHeight}"
-                                MinWidth="{TemplateBinding MinWidth}"
-                                MaxWidth="{TemplateBinding MaxWidth}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"
                                 Padding="{StaticResource ExpanderContentPadding}">

From 0c58a25795740848a7cda7f0ac3bc6d828a227b8 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 15:04:07 -0500
Subject: [PATCH 08/22] Update Expander test page

---
 dev/Expander/TestUI/ExpanderPage.xaml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index 3d89b58e65..d6b00b674a 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -29,7 +29,7 @@
                 <Button AutomationProperties.AutomationId="ExpandedExpanderContent">Content</Button>
             </controls:Expander>
 
-            <controls:Expander AutomationProperties.AutomationId="CollapsedExpander" AutomationProperties.Name="Expander2" IsExpanded="False" Margin="12" MaxWidth="{ThemeResource FlyoutThemeMaxWidth}">
+            <controls:Expander AutomationProperties.AutomationId="CollapsedExpander" AutomationProperties.Name="Expander2" IsExpanded="False" Margin="12" Width="{ThemeResource FlyoutThemeMaxWidth}">
                 <controls:Expander.Header>
                     <TextBlock Text="This expander is collapsed by default. This is a long title to test the header width. ext should be wrapping here." TextWrapping="Wrap" Margin="0,12,0,13"/>
                 </controls:Expander.Header>
@@ -74,12 +74,12 @@
                 </controls:Expander>
             </local:TestControl>
 
-            <controls:Expander AutomationProperties.Name="ExpanderStretched" ExpandDirection="Down" IsExpanded="True" Margin="12" HorizontalAlignment="Stretch">
+            <controls:Expander AutomationProperties.Name="ExpanderStretched" ExpandDirection="Down" IsExpanded="True" Margin="12" HorizontalAlignment="Stretch" HorizontalContentAlignment="Right">
                 <controls:Expander.Header>
                     <TextBlock Margin="0,0,0,1">This expander stretches along with its content</TextBlock>
                 </controls:Expander.Header>
                 <StackPanel HorizontalAlignment="Right">
-                    <TextBlock TextAlignment="Right">Content</TextBlock>
+                    <TextBlock>Right Content</TextBlock>
                 </StackPanel>
             </controls:Expander>
         </StackPanel>

From 25e8c59acb8fe3089cae3a09dae18fbb3cc0f148 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 16:10:12 -0500
Subject: [PATCH 09/22] Add fixed-height Expander example

---
 dev/Expander/TestUI/ExpanderPage.xaml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index d6b00b674a..ed6383d731 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -82,6 +82,16 @@
                     <TextBlock>Right Content</TextBlock>
                 </StackPanel>
             </controls:Expander>
+
+            <controls:Expander AutomationProperties.Name="ExpanderSetHeight" ExpandDirection="Down" IsExpanded="False" Margin="12" Height="150" MaxWidth="{ThemeResource FlyoutThemeMaxWidth}">
+                <controls:Expander.Header>
+                    <TextBlock Margin="0,0,0,1">This expander sets a fixed height</TextBlock>
+                </controls:Expander.Header>
+                <ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
+                    <TextBlock TextWrapping="Wrap">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec id lacinia tellus. Integer eu mollis leo, ornare ultricies neque. Sed diam lectus, varius sed justo vel, malesuada condimentum lorem. Proin porttitor quis enim a facilisis. Suspendisse vehicula imperdiet egestas. Suspendisse imperdiet, ipsum in commodo cursus, mi nisl volutpat nulla, in interdum mi nulla a nulla. Cras feugiat odio ac eros ullamcorper suscipit. Praesent ultricies ligula eget efficitur tristique. Donec imperdiet ultrices dolor sollicitudin bibendum. In hac habitasse platea dictumst. Fusce vel lacinia purus. Sed tempor est sed suscipit luctus. Aenean laoreet tellus vitae efficitur scelerisque. Sed suscipit risus ac nisl rhoncus hendrerit.</TextBlock>
+                </ScrollViewer>
+            </controls:Expander>
+            
         </StackPanel>
 
     </ScrollViewer>

From 585b15cde724efc309a3ed6e2852fb49584af97a Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 18:43:13 -0500
Subject: [PATCH 10/22] Stretch header content

---
 dev/Expander/Expander.xaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index cc87459277..392d77e2bc 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -135,10 +135,12 @@
                             IsEnabled="{TemplateBinding IsEnabled}"
                             Padding="{TemplateBinding Padding}"
                             Style="{StaticResource ExpanderHeaderDownStyle}"
+                            HorizontalAlignment="Stretch"
+                            HorizontalContentAlignment="Stretch"
+                            VerticalContentAlignment="Stretch"
                             Content="{TemplateBinding Header}"
                             ContentTemplate="{TemplateBinding HeaderTemplate}"
                             ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
-                            HorizontalAlignment="Stretch"
                             IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" />
                         <!-- The clip is a composition clip applied in code -->
                         <Border x:Name="ExpanderContentClip" Grid.Row="1">

From 21c73eb44f53cdfbc8f21bf031af4ee3bf723a99 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 18:48:35 -0500
Subject: [PATCH 11/22] Standardize resource names

---
 dev/Expander/Expander.xaml                |  8 ++++----
 dev/Expander/Expander_themeresources.xaml | 16 ++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 392d77e2bc..e7ab00faff 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -108,7 +108,7 @@
                                 <VisualState x:Name="Up">
                                     <VisualState.Setters>
                                         <Setter Target="ExpanderHeader.Style" Value="{StaticResource ExpanderHeaderUpStyle}" />
-                                        <Setter Target="ExpanderContent.BorderThickness" Value="{StaticResource ExpanderDropdownUpBorderThickness}" />
+                                        <Setter Target="ExpanderContent.BorderThickness" Value="{StaticResource ExpanderContentUpBorderThickness}" />
                                         <contract7Present:Setter Target="ExpanderContent.CornerRadius" Value="{Binding CornerRadius, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource TopCornerRadiusFilterConverter}}" />
                                         <Setter Target="ExpanderHeader.(Grid.Row)" Value="1" />
                                         <Setter Target="ExpanderContentClip.(Grid.Row)" Value="0" />
@@ -147,11 +147,11 @@
                             <Border
                                 x:Name="ExpanderContent"
                                 Visibility="Collapsed"
-                                Background="{ThemeResource ExpanderDropDownBackground}"
+                                Background="{ThemeResource ExpanderContentBackground}"
                                 contract7Present:BackgroundSizing="{TemplateBinding BackgroundSizing}"
                                 contract7Present:CornerRadius="{Binding CornerRadius, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource BottomCornerRadiusFilterConverter}}"
-                                BorderBrush="{ThemeResource ExpanderDropDownBorderBrush}"
-                                BorderThickness="{StaticResource ExpanderDropdownDownBorderThickness}"
+                                BorderBrush="{ThemeResource ExpanderContentBorderBrush}"
+                                BorderThickness="{StaticResource ExpanderContentDownBorderThickness}"
                                 MinHeight="{TemplateBinding MinHeight}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"
diff --git a/dev/Expander/Expander_themeresources.xaml b/dev/Expander/Expander_themeresources.xaml
index 76d228a550..e6dd1e621b 100644
--- a/dev/Expander/Expander_themeresources.xaml
+++ b/dev/Expander/Expander_themeresources.xaml
@@ -16,8 +16,8 @@
             <StaticResource x:Key="ExpanderBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderDropDownBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderDropDownBorderBrush" ResourceKey="ExpanderBorderBrush" />
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderBorderBrush" />
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SubtleFillColorSecondaryBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SubtleFillColorTertiaryBrush" />
@@ -42,8 +42,8 @@
             <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             
-            <StaticResource x:Key="ExpanderDropDownBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderDropDownBorderBrush" ResourceKey="ExpanderBorderBrush" />
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderBorderBrush" />
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SubtleFillColorSecondaryBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SubtleFillColorTertiaryBrush" />
@@ -67,8 +67,8 @@
             <StaticResource x:Key="ExpanderBorderBrush" ResourceKey="SystemColorButtonTextColorBrush" />
             <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="SystemColorHighlightColorBrush" />
             <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderDropDownBackground" ResourceKey="SystemColorWindowColorBrush" />
-            <StaticResource x:Key="ExpanderDropDownBorderBrush" ResourceKey="SystemColorWindowTextColorBrush" />
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="SystemColorWindowColorBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="SystemColorWindowTextColorBrush" />
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SystemColorButtonFaceColorBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SystemControlTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SystemControlTransparentBrush" />
@@ -92,8 +92,8 @@
     <x:Double x:Key="ExpanderMinHeight">48</x:Double>
     <Thickness x:Key="ExpanderContentPadding">16</Thickness>
     <Thickness x:Key="ExpanderHeaderPadding">16,0,0,0</Thickness>
-    <Thickness x:Key="ExpanderDropdownDownBorderThickness">1,0,1,1</Thickness>
-    <Thickness x:Key="ExpanderDropdownUpBorderThickness">1,1,1,0</Thickness>
+    <Thickness x:Key="ExpanderContentDownBorderThickness">1,0,1,1</Thickness>
+    <Thickness x:Key="ExpanderContentUpBorderThickness">1,1,1,0</Thickness>
 
     <Style x:Key="ExpanderHeaderDownStyle" TargetType="ToggleButton">
         <Setter Property="Padding" Value="{StaticResource ExpanderHeaderPadding}"/>

From f2d4e00d79e84b2a60558390b2bb7244040abaca Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 2 Mar 2021 18:54:52 -0500
Subject: [PATCH 12/22] The header VerticalContentAlignment must be center

---
 dev/Expander/Expander.xaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index e7ab00faff..3c21d6e655 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -137,7 +137,7 @@
                             Style="{StaticResource ExpanderHeaderDownStyle}"
                             HorizontalAlignment="Stretch"
                             HorizontalContentAlignment="Stretch"
-                            VerticalContentAlignment="Stretch"
+                            VerticalContentAlignment="Center"
                             Content="{TemplateBinding Header}"
                             ContentTemplate="{TemplateBinding HeaderTemplate}"
                             ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"

From 77554a7ea83bccca4440357fb5c97e7e630f4b2a Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 16:04:11 -0500
Subject: [PATCH 13/22] Revert "Rename 'Expanding' to 'Expanded'"

This reverts commit 1223fb1ef579013ba0594062b51635a35b3aee8c.
---
 dev/Expander/Expander.cpp             |  6 +++---
 dev/Expander/Expander.h               |  2 +-
 dev/Expander/Expander.idl             |  4 ++--
 dev/Generated/Expander.properties.cpp | 10 +++++-----
 dev/Generated/Expander.properties.h   |  6 +++---
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/dev/Expander/Expander.cpp b/dev/Expander/Expander.cpp
index 2facc11aad..da39e2c38b 100644
--- a/dev/Expander/Expander.cpp
+++ b/dev/Expander/Expander.cpp
@@ -91,9 +91,9 @@ void Expander::OnContentSizeChanged(const winrt::IInspectable&, const winrt::Siz
 }
 
 
-void Expander::RaiseExpandedEvent(const winrt::Expander& container)
+void Expander::RaiseExpandingEvent(const winrt::Expander& container)
 {
-    m_expandedEventSource(*this, nullptr);
+    m_expandingEventSource(*this, nullptr);
 }
 
 void Expander::RaiseCollapsedEvent(const winrt::Expander& container)
@@ -107,7 +107,7 @@ void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChange
 
     if (IsExpanded())
     {
-        RaiseExpandedEvent(*this);
+        RaiseExpandingEvent(*this);
     }
     else
     {
diff --git a/dev/Expander/Expander.h b/dev/Expander/Expander.h
index efc374f2af..01879908c4 100644
--- a/dev/Expander/Expander.h
+++ b/dev/Expander/Expander.h
@@ -26,7 +26,7 @@ class Expander :
     void OnApplyTemplate();
 
 
-    void RaiseExpandedEvent(const winrt::Expander& container);
+    void RaiseExpandingEvent(const winrt::Expander& container);
     void RaiseCollapsedEvent(const winrt::Expander& container);
 
     void OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& args);
diff --git a/dev/Expander/Expander.idl b/dev/Expander/Expander.idl
index c1b57e6a97..04744fbbec 100644
--- a/dev/Expander/Expander.idl
+++ b/dev/Expander/Expander.idl
@@ -27,7 +27,7 @@ unsealed runtimeclass Expander : Windows.UI.Xaml.Controls.ContentControl
     [MUX_PROPERTY_CHANGED_CALLBACK(TRUE)]
     ExpandDirection ExpandDirection{ get; set; };
 
-    event Windows.Foundation.TypedEventHandler<Expander, ExpanderExpandedEventArgs> Expanded;
+    event Windows.Foundation.TypedEventHandler<Expander, ExpanderExpandingEventArgs> Expanding;
     event Windows.Foundation.TypedEventHandler<Expander, ExpanderCollapsedEventArgs> Collapsed;
 
     [MUX_PROPERTY_NEEDS_DP_FIELD]
@@ -52,7 +52,7 @@ enum ExpandDirection
 [MUX_PUBLIC]
 [default_interface]
 [webhosthidden]
-runtimeclass ExpanderExpandedEventArgs
+runtimeclass ExpanderExpandingEventArgs
 {
 }
 
diff --git a/dev/Generated/Expander.properties.cpp b/dev/Generated/Expander.properties.cpp
index 4ad32a5b4c..db76982530 100644
--- a/dev/Generated/Expander.properties.cpp
+++ b/dev/Generated/Expander.properties.cpp
@@ -22,7 +22,7 @@ GlobalDependencyProperty ExpanderProperties::s_TemplateSettingsProperty{ nullptr
 
 ExpanderProperties::ExpanderProperties()
     : m_collapsedEventSource{static_cast<Expander*>(this)}
-    , m_expandedEventSource{static_cast<Expander*>(this)}
+    , m_expandingEventSource{static_cast<Expander*>(this)}
 {
     EnsureProperties();
 }
@@ -211,12 +211,12 @@ void ExpanderProperties::Collapsed(winrt::event_token const& token)
     m_collapsedEventSource.remove(token);
 }
 
-winrt::event_token ExpanderProperties::Expanded(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs> const& value)
+winrt::event_token ExpanderProperties::Expanding(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs> const& value)
 {
-    return m_expandedEventSource.add(value);
+    return m_expandingEventSource.add(value);
 }
 
-void ExpanderProperties::Expanded(winrt::event_token const& token)
+void ExpanderProperties::Expanding(winrt::event_token const& token)
 {
-    m_expandedEventSource.remove(token);
+    m_expandingEventSource.remove(token);
 }
diff --git a/dev/Generated/Expander.properties.h b/dev/Generated/Expander.properties.h
index b28adb4e5f..70534be0e3 100644
--- a/dev/Generated/Expander.properties.h
+++ b/dev/Generated/Expander.properties.h
@@ -43,11 +43,11 @@ class ExpanderProperties
 
     winrt::event_token Collapsed(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderCollapsedEventArgs> const& value);
     void Collapsed(winrt::event_token const& token);
-    winrt::event_token Expanded(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs> const& value);
-    void Expanded(winrt::event_token const& token);
+    winrt::event_token Expanding(winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs> const& value);
+    void Expanding(winrt::event_token const& token);
 
     event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderCollapsedEventArgs>> m_collapsedEventSource;
-    event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandedEventArgs>> m_expandedEventSource;
+    event_source<winrt::TypedEventHandler<winrt::Expander, winrt::ExpanderExpandingEventArgs>> m_expandingEventSource;
 
     static void EnsureProperties();
     static void ClearProperties();

From 6a72d3919adc863b2c68bbf9f7235e4a080cc066 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 16:04:17 -0500
Subject: [PATCH 14/22] Revert "Ensure Expanded/Collapsed fire after state is
 applied"

This reverts commit 363c732069c5c2f050a2a7a58c59671e0611b12d.
---
 dev/Expander/Expander.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/dev/Expander/Expander.cpp b/dev/Expander/Expander.cpp
index da39e2c38b..a2f22bf3cd 100644
--- a/dev/Expander/Expander.cpp
+++ b/dev/Expander/Expander.cpp
@@ -103,8 +103,6 @@ void Expander::RaiseCollapsedEvent(const winrt::Expander& container)
 
 void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)
 {
-    UpdateExpandState(true);
-
     if (IsExpanded())
     {
         RaiseExpandingEvent(*this);
@@ -113,6 +111,7 @@ void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChange
     {
         RaiseCollapsedEvent(*this);
     }
+    UpdateExpandState(true);
 }
 
 void Expander::OnExpandDirectionPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)

From 210ca0c32e30baac9cac8027dc8be531dbe8b2c0 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 16:18:13 -0500
Subject: [PATCH 15/22] Padding now applies to the Content area

---
 dev/Expander/Expander.xaml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index 3c21d6e655..f65558e184 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -26,7 +26,7 @@
         <Setter Property="MinHeight" Value="{StaticResource ExpanderMinHeight}" />
         <Setter Property="BorderThickness" Value="{ThemeResource ExpanderBorderThickness}" />
         <Setter Property="BorderBrush" Value="{ThemeResource ExpanderBorderBrush}" />
-        <Setter Property="Padding" Value="{StaticResource ExpanderHeaderPadding}" />
+        <Setter Property="Padding" Value="{StaticResource ExpanderContentPadding}" />
         <Setter Property="HorizontalAlignment" Value="Left" />
         <Setter Property="VerticalAlignment" Value="Center" />
         <contract7Present:Setter Property="CornerRadius" Value="{ThemeResource ControlCornerRadius}" />
@@ -133,7 +133,7 @@
                             MinHeight="{TemplateBinding MinHeight}"
                             contract7Present:CornerRadius="{TemplateBinding CornerRadius}"
                             IsEnabled="{TemplateBinding IsEnabled}"
-                            Padding="{TemplateBinding Padding}"
+                            Padding="{StaticResource ExpanderHeaderPadding}"
                             Style="{StaticResource ExpanderHeaderDownStyle}"
                             HorizontalAlignment="Stretch"
                             HorizontalContentAlignment="Stretch"
@@ -155,7 +155,7 @@
                                 MinHeight="{TemplateBinding MinHeight}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"
-                                Padding="{StaticResource ExpanderContentPadding}">
+                                Padding="{TemplateBinding Padding}">
                                 <ContentPresenter
                                     Content="{TemplateBinding Content}"
                                     ContentTemplate="{TemplateBinding ContentTemplate}"

From f081da44aae8305561b14e5260b66e5a771470fc Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 17:43:54 -0500
Subject: [PATCH 16/22] Reorg and rename expander theme resources

- Header and content resources are clearly named and separated
- Relevant control properties now apply to the content area instead of header
---
 dev/Expander/Expander.xaml                |  18 +--
 dev/Expander/Expander_themeresources.xaml | 184 ++++++++++++----------
 2 files changed, 112 insertions(+), 90 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index f65558e184..d60b17327f 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -20,12 +20,12 @@
                Without this override, the narrator user that focuses the expander on a touch screen will see that pressing "Tab"
                doesn't work how they would expect.-->
         <Setter Property="IsTabStop" Value="False"/>
-        <Setter Property="Background" Value="{ThemeResource ExpanderBackground}" />
+        <Setter Property="Background" Value="{ThemeResource ExpanderContentBackground}" />
         <contract7Present:Setter Property="BackgroundSizing" Value="InnerBorderEdge" />
         <Setter Property="MinWidth" Value="{ThemeResource FlyoutThemeMinWidth}" />
         <Setter Property="MinHeight" Value="{StaticResource ExpanderMinHeight}" />
-        <Setter Property="BorderThickness" Value="{ThemeResource ExpanderBorderThickness}" />
-        <Setter Property="BorderBrush" Value="{ThemeResource ExpanderBorderBrush}" />
+        <Setter Property="BorderThickness" Value="{ThemeResource ExpanderContentDownBorderThickness}" />
+        <Setter Property="BorderBrush" Value="{ThemeResource ExpanderContentBorderBrush}" />
         <Setter Property="Padding" Value="{StaticResource ExpanderContentPadding}" />
         <Setter Property="HorizontalAlignment" Value="Left" />
         <Setter Property="VerticalAlignment" Value="Center" />
@@ -126,10 +126,10 @@
                         <ToggleButton
                             x:Name="ExpanderHeader"
                             AutomationProperties.AutomationId="ExpanderToggleButton"
-                            Background="{TemplateBinding Background}"
+                            Background="{ThemeResource ExpanderHeaderBackground}"
                             contract7Present:BackgroundSizing="{TemplateBinding BackgroundSizing}"
-                            BorderBrush="{TemplateBinding BorderBrush}"
-                            BorderThickness="{TemplateBinding BorderThickness}"
+                            BorderBrush="{ThemeResource ExpanderHeaderBorderBrush}"
+                            BorderThickness="{ThemeResource ExpanderHeaderBorderThickness}"
                             MinHeight="{TemplateBinding MinHeight}"
                             contract7Present:CornerRadius="{TemplateBinding CornerRadius}"
                             IsEnabled="{TemplateBinding IsEnabled}"
@@ -147,11 +147,11 @@
                             <Border
                                 x:Name="ExpanderContent"
                                 Visibility="Collapsed"
-                                Background="{ThemeResource ExpanderContentBackground}"
+                                Background="{TemplateBinding Background}"
                                 contract7Present:BackgroundSizing="{TemplateBinding BackgroundSizing}"
                                 contract7Present:CornerRadius="{Binding CornerRadius, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource BottomCornerRadiusFilterConverter}}"
-                                BorderBrush="{ThemeResource ExpanderContentBorderBrush}"
-                                BorderThickness="{StaticResource ExpanderContentDownBorderThickness}"
+                                BorderBrush="{TemplateBinding BorderBrush}"
+                                BorderThickness="{TemplateBinding BorderThickness}"
                                 MinHeight="{TemplateBinding MinHeight}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"
diff --git a/dev/Expander/Expander_themeresources.xaml b/dev/Expander/Expander_themeresources.xaml
index c64fc488e1..770f794952 100644
--- a/dev/Expander/Expander_themeresources.xaml
+++ b/dev/Expander/Expander_themeresources.xaml
@@ -9,15 +9,19 @@
 
     <ResourceDictionary.ThemeDictionaries>
         <ResourceDictionary x:Key="Dark">
-            <StaticResource x:Key="ExpanderBackground" ResourceKey="CardBackgroundFillColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderForeground" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderForegroundPointerOver" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderForegroundPressed" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderBorderBrush" />
+
+            <!-- Header -->
+            <StaticResource x:Key="ExpanderHeaderBackground" ResourceKey="CardBackgroundFillColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderForeground" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPointerOver" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPressed" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <Thickness x:Key="ExpanderHeaderBorderThickness">1</Thickness>
+            
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SubtleFillColorSecondaryBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SubtleFillColorTertiaryBrush" />
@@ -27,23 +31,28 @@
             <StaticResource x:Key="ExpanderChevronBorderBrush" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPointerOverBrush" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPressedBrush" ResourceKey="SubtleFillColorTransparentBrush" />
-            <StaticResource x:Key="ExpanderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
-            <StaticResource x:Key="ExpanderDisabledBorderBrush" ResourceKey="ExpanderBorderBrush" />
-            <Thickness x:Key="ExpanderBorderThickness">1</Thickness>
             <Thickness x:Key="ExpanderChevronBorderThickness">0</Thickness>
+
+            <!-- Content -->
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+
         </ResourceDictionary>
 
         <ResourceDictionary x:Key="Light">
-            <StaticResource x:Key="ExpanderBackground" ResourceKey="CardBackgroundFillColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderForeground" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderForegroundPointerOver" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderForegroundPressed" ResourceKey="TextFillColorPrimaryBrush" />
-            <StaticResource x:Key="ExpanderBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
-            
-            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderBorderBrush" />
+
+            <!-- Header -->
+            <StaticResource x:Key="ExpanderHeaderBackground" ResourceKey="CardBackgroundFillColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderForeground" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPointerOver" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPressed" ResourceKey="TextFillColorPrimaryBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <Thickness x:Key="ExpanderHeaderBorderThickness">1</Thickness>
+
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SubtleFillColorSecondaryBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SubtleFillColorTertiaryBrush" />
@@ -53,22 +62,28 @@
             <StaticResource x:Key="ExpanderChevronBorderBrush" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPointerOverBrush" ResourceKey="SubtleFillColorTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPressedBrush" ResourceKey="SubtleFillColorTransparentBrush" />
-            <StaticResource x:Key="ExpanderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
-            <StaticResource x:Key="ExpanderDisabledBorderBrush" ResourceKey="ExpanderBorderBrush" />
-            <Thickness x:Key="ExpanderBorderThickness">1</Thickness>
             <Thickness x:Key="ExpanderChevronBorderThickness">0</Thickness>
+
+            <!-- Content -->
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+
         </ResourceDictionary>
 
         <ResourceDictionary x:Key="HighContrast">
-            <StaticResource x:Key="ExpanderBackground" ResourceKey="SystemColorButtonFaceColorBrush" />
-            <StaticResource x:Key="ExpanderForeground" ResourceKey="SystemColorButtonTextColorBrush" />
-            <StaticResource x:Key="ExpanderForegroundPointerOver" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderForegroundPressed" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderBorderBrush" ResourceKey="SystemColorButtonTextColorBrush" />
-            <StaticResource x:Key="ExpanderBorderPointerOverBrush" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderBorderPressedBrush" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="SystemColorWindowColorBrush" />
-            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="SystemColorWindowTextColorBrush" />
+
+            <!-- Header -->
+            <StaticResource x:Key="ExpanderHeaderBackground" ResourceKey="SystemColorButtonFaceColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderForeground" ResourceKey="SystemColorButtonTextColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPointerOver" ResourceKey="SystemColorHighlightColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderForegroundPressed" ResourceKey="SystemColorHighlightColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderBrush" ResourceKey="SystemColorButtonTextColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPointerOverBrush" ResourceKey="SystemColorHighlightColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderBorderPressedBrush" ResourceKey="SystemColorHighlightColorBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="TextFillColorDisabledBrush" />
+            <Thickness x:Key="ExpanderHeaderBorderThickness">2</Thickness>
+
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SystemColorButtonFaceColorBrush" />
             <StaticResource x:Key="ExpanderChevronPointerOverBackground" ResourceKey="SystemControlTransparentBrush" />
             <StaticResource x:Key="ExpanderChevronPressedBackground" ResourceKey="SystemControlTransparentBrush" />
@@ -78,21 +93,28 @@
             <StaticResource x:Key="ExpanderChevronBorderBrush" ResourceKey="SystemColorButtonTextColorBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPointerOverBrush" ResourceKey="SystemColorHighlightColorBrush" />
             <StaticResource x:Key="ExpanderChevronBorderPressedBrush" ResourceKey="SystemColorHighlightColorBrush" />
-            <StaticResource x:Key="ExpanderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
-            <StaticResource x:Key="ExpanderDisabledBorderBrush" ResourceKey="TextFillColorDisabledBrush" />
-            <Thickness x:Key="ExpanderBorderThickness">2</Thickness>
             <Thickness x:Key="ExpanderChevronBorderThickness">2</Thickness>
+
+            <!-- Content -->
+            <StaticResource x:Key="ExpanderContentBackground" ResourceKey="SystemColorWindowColorBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="SystemColorWindowTextColorBrush" />
+
         </ResourceDictionary>
     </ResourceDictionary.ThemeDictionaries>
 
+    <!-- Shared header/content -->
+    <x:Double x:Key="ExpanderMinHeight">48</x:Double>
+
+    <!-- Header -->
+    <Thickness x:Key="ExpanderHeaderPadding">16,0,0,0</Thickness>
     <Thickness x:Key="ExpanderChevronMargin">20,0,8,0</Thickness>
     <x:String x:Key="ExpanderChevronUpGlyph">&#xE70E;</x:String>
     <x:String x:Key="ExpanderChevronDownGlyph">&#xE70D;</x:String>
     <x:Double x:Key="ExpanderChevronButtonSize">32</x:Double>
     <x:Double x:Key="ExpanderChevronGlyphSize">12</x:Double>
-    <x:Double x:Key="ExpanderMinHeight">48</x:Double>
+
+    <!-- Content -->
     <Thickness x:Key="ExpanderContentPadding">16</Thickness>
-    <Thickness x:Key="ExpanderHeaderPadding">16,0,0,0</Thickness>
     <Thickness x:Key="ExpanderContentDownBorderThickness">1,0,1,1</Thickness>
     <Thickness x:Key="ExpanderContentUpBorderThickness">1,1,1,0</Thickness>
 
@@ -113,7 +135,7 @@
                         MaxWidth="{TemplateBinding MaxWidth}"
                         Width="{TemplateBinding Width}"
                         HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
-                        BorderBrush="{ThemeResource ExpanderBorderBrush}"
+                        BorderBrush="{ThemeResource ExpanderHeaderBorderBrush}"
                         BorderThickness="{TemplateBinding BorderThickness}"
                         Padding="{TemplateBinding Padding}">
                         <Grid.ColumnDefinitions>
@@ -126,10 +148,10 @@
                                 <VisualState x:Name="Normal">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronForeground}" />
@@ -145,10 +167,10 @@
                                 <VisualState x:Name="PointerOver">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPointerOver}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPointerOver}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPointerOverBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPointerOverBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPointerOverForeground}" />
@@ -167,10 +189,10 @@
                                 <VisualState x:Name="Pressed">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPressed}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPressed}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPressedBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPressedBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPressedForeground}" />
@@ -189,16 +211,16 @@
                                 <VisualState x:Name="Disabled">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="Background">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronBackground}" />
@@ -212,10 +234,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronForeground}" />
@@ -238,10 +260,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPointerOver}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPointerOver}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPointerOverBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPointerOverBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPointerOverForeground}" />
@@ -264,10 +286,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPressed}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPressed}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPressedBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPressedBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPressedForeground}" />
@@ -291,16 +313,16 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="Background">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronBackground}" />
@@ -385,7 +407,7 @@
                         MaxWidth="{TemplateBinding MaxWidth}"
                         Width="{TemplateBinding Width}"
                         HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
-                        BorderBrush="{ThemeResource ExpanderBorderBrush}"
+                        BorderBrush="{ThemeResource ExpanderHeaderBorderBrush}"
                         BorderThickness="{TemplateBinding BorderThickness}"
                         Padding="{TemplateBinding Padding}">
                         <Grid.ColumnDefinitions>
@@ -398,10 +420,10 @@
                                 <VisualState x:Name="Normal">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronForeground}" />
@@ -417,10 +439,10 @@
                                 <VisualState x:Name="PointerOver">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPointerOver}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPointerOver}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPointerOverBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPointerOverBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPointerOverForeground}" />
@@ -439,10 +461,10 @@
                                 <VisualState x:Name="Pressed">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPressed}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPressed}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPressedBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPressedBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPressedForeground}" />
@@ -461,16 +483,16 @@
                                 <VisualState x:Name="Disabled">
                                     <Storyboard>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="Background">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronBackground}" />
@@ -484,10 +506,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronForeground}" />
@@ -510,10 +532,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPointerOver}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPointerOver}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPointerOverBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPointerOverBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPointerOverForeground}" />
@@ -536,10 +558,10 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderForegroundPressed}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderForegroundPressed}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderBorderPressedBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderBorderPressedBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronPressedForeground}" />
@@ -563,16 +585,16 @@
                                             Storyboard.TargetProperty="Angle"
                                             To="180.0" Duration="0:0:0.1"/>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ToggleButtonGrid" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevron" Storyboard.TargetProperty="Foreground">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledForeground}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledForeground}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="BorderBrush">
-                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderDisabledBorderBrush}" />
+                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderHeaderDisabledBorderBrush}" />
                                         </ObjectAnimationUsingKeyFrames>
                                         <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ExpandCollapseChevronBorder" Storyboard.TargetProperty="Background">
                                             <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ExpanderChevronBackground}" />

From 2a45b778c6bdaeb55364ca7913059a0b4ff0cdbe Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 19:48:04 -0500
Subject: [PATCH 17/22] Work-around DP precedence issue

- Border thickness of the content area is no longer controlled by the BorderThickness DP of the control itself
- This is required as BorderThickness of the control has local precedence over the visual state setter.
- The correct solution for this is another filter converter for border thickness
---
 dev/Expander/Expander.xaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index d60b17327f..b6656ccaba 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -151,7 +151,7 @@
                                 contract7Present:BackgroundSizing="{TemplateBinding BackgroundSizing}"
                                 contract7Present:CornerRadius="{Binding CornerRadius, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource BottomCornerRadiusFilterConverter}}"
                                 BorderBrush="{TemplateBinding BorderBrush}"
-                                BorderThickness="{TemplateBinding BorderThickness}"
+                                BorderThickness="{StaticResource ExpanderContentDownBorderThickness}"
                                 MinHeight="{TemplateBinding MinHeight}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"

From 9e9a8107a4e49d9aed1818f57f91d569456e6cdc Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 19:57:45 -0500
Subject: [PATCH 18/22] Add resources to control header content alignment

---
 dev/Expander/Expander.xaml                | 4 ++--
 dev/Expander/Expander_themeresources.xaml | 2 ++
 dev/Expander/TestUI/ExpanderPage.xaml     | 4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index b6656ccaba..f719a79222 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -136,8 +136,8 @@
                             Padding="{StaticResource ExpanderHeaderPadding}"
                             Style="{StaticResource ExpanderHeaderDownStyle}"
                             HorizontalAlignment="Stretch"
-                            HorizontalContentAlignment="Stretch"
-                            VerticalContentAlignment="Center"
+                            HorizontalContentAlignment="{ThemeResource ExpanderHeaderHorizontalContentAlignment}"
+                            VerticalContentAlignment="{ThemeResource ExpanderHeaderVerticalContentAlignment}"
                             Content="{TemplateBinding Header}"
                             ContentTemplate="{TemplateBinding HeaderTemplate}"
                             ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
diff --git a/dev/Expander/Expander_themeresources.xaml b/dev/Expander/Expander_themeresources.xaml
index 770f794952..97c6f843a0 100644
--- a/dev/Expander/Expander_themeresources.xaml
+++ b/dev/Expander/Expander_themeresources.xaml
@@ -106,6 +106,8 @@
     <x:Double x:Key="ExpanderMinHeight">48</x:Double>
 
     <!-- Header -->
+    <HorizontalAlignment x:Key="ExpanderHeaderHorizontalContentAlignment">Stretch</HorizontalAlignment>
+    <VerticalAlignment x:Key="ExpanderHeaderVerticalContentAlignment">Center</VerticalAlignment>
     <Thickness x:Key="ExpanderHeaderPadding">16,0,0,0</Thickness>
     <Thickness x:Key="ExpanderChevronMargin">20,0,8,0</Thickness>
     <x:String x:Key="ExpanderChevronUpGlyph">&#xE70E;</x:String>
diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index ed6383d731..68011add7a 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -76,10 +76,10 @@
 
             <controls:Expander AutomationProperties.Name="ExpanderStretched" ExpandDirection="Down" IsExpanded="True" Margin="12" HorizontalAlignment="Stretch" HorizontalContentAlignment="Right">
                 <controls:Expander.Header>
-                    <TextBlock Margin="0,0,0,1">This expander stretches along with its content</TextBlock>
+                    <TextBlock HorizontalAlignment="Right" Margin="0,0,0,1">This expander stretches along with its content</TextBlock>
                 </controls:Expander.Header>
                 <StackPanel HorizontalAlignment="Right">
-                    <TextBlock>Right Content</TextBlock>
+                    <TextBlock>Header and Content is right aligned</TextBlock>
                 </StackPanel>
             </controls:Expander>
 

From 654395239a0a9fd5eb6d92ced6b6f337f3428e43 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 20:11:11 -0500
Subject: [PATCH 19/22] Fix Expander event ordering

---
 dev/Expander/Expander.cpp | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/dev/Expander/Expander.cpp b/dev/Expander/Expander.cpp
index a2f22bf3cd..3497d0958e 100644
--- a/dev/Expander/Expander.cpp
+++ b/dev/Expander/Expander.cpp
@@ -103,15 +103,27 @@ void Expander::RaiseCollapsedEvent(const winrt::Expander& container)
 
 void Expander::OnIsExpandedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)
 {
-    if (IsExpanded())
+    const auto isExpanded = IsExpanded();
+
+    if (isExpanded)
     {
         RaiseExpandingEvent(*this);
     }
     else
     {
-        RaiseCollapsedEvent(*this);
+        // Available for a 'Collapsing' event
     }
+
     UpdateExpandState(true);
+
+    if (isExpanded)
+    {
+        // Available for an 'Expanded' event
+    }
+    else
+    {
+        RaiseCollapsedEvent(*this);
+    }
 }
 
 void Expander::OnExpandDirectionPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& /*args*/)

From cf8bcef4058f1b4f605fffb01504ad99ac25d03c Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Fri, 12 Mar 2021 20:40:46 -0500
Subject: [PATCH 20/22] Fix some Static not Theme resources

---
 dev/Expander/Expander.xaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dev/Expander/Expander.xaml b/dev/Expander/Expander.xaml
index f719a79222..93e1ac17a0 100644
--- a/dev/Expander/Expander.xaml
+++ b/dev/Expander/Expander.xaml
@@ -136,8 +136,8 @@
                             Padding="{StaticResource ExpanderHeaderPadding}"
                             Style="{StaticResource ExpanderHeaderDownStyle}"
                             HorizontalAlignment="Stretch"
-                            HorizontalContentAlignment="{ThemeResource ExpanderHeaderHorizontalContentAlignment}"
-                            VerticalContentAlignment="{ThemeResource ExpanderHeaderVerticalContentAlignment}"
+                            HorizontalContentAlignment="{StaticResource ExpanderHeaderHorizontalContentAlignment}"
+                            VerticalContentAlignment="{StaticResource ExpanderHeaderVerticalContentAlignment}"
                             Content="{TemplateBinding Header}"
                             ContentTemplate="{TemplateBinding HeaderTemplate}"
                             ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"

From ece7611ad7f780c0847435be0574bc620bcf5157 Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 16 Mar 2021 01:03:44 -0400
Subject: [PATCH 21/22] Remove some resource redirections

There is concern these would not be re-evaluated when expected
---
 dev/Expander/Expander_themeresources.xaml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/dev/Expander/Expander_themeresources.xaml b/dev/Expander/Expander_themeresources.xaml
index 97c6f843a0..e50edeef26 100644
--- a/dev/Expander/Expander_themeresources.xaml
+++ b/dev/Expander/Expander_themeresources.xaml
@@ -19,7 +19,7 @@
             <StaticResource x:Key="ExpanderHeaderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderHeaderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderHeaderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
-            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <Thickness x:Key="ExpanderHeaderBorderThickness">1</Thickness>
             
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
@@ -35,7 +35,7 @@
 
             <!-- Content -->
             <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
 
         </ResourceDictionary>
 
@@ -50,7 +50,7 @@
             <StaticResource x:Key="ExpanderHeaderBorderPointerOverBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderHeaderBorderPressedBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <StaticResource x:Key="ExpanderHeaderDisabledForeground" ResourceKey="TextFillColorDisabledBrush" />
-            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <StaticResource x:Key="ExpanderHeaderDisabledBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
             <Thickness x:Key="ExpanderHeaderBorderThickness">1</Thickness>
 
             <StaticResource x:Key="ExpanderChevronBackground" ResourceKey="SubtleFillColorTransparentBrush" />
@@ -66,7 +66,7 @@
 
             <!-- Content -->
             <StaticResource x:Key="ExpanderContentBackground" ResourceKey="CardBackgroundFillColorSecondaryBrush" />
-            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="ExpanderHeaderBorderBrush" />
+            <StaticResource x:Key="ExpanderContentBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
 
         </ResourceDictionary>
 

From 53d69f46db358edd5df54d7d8f277a02d8dd86da Mon Sep 17 00:00:00 2001
From: robloo <robert.looyengoed@gmail.com>
Date: Tue, 16 Mar 2021 01:04:09 -0400
Subject: [PATCH 22/22] Remove unnecessary margins

---
 dev/Expander/TestUI/ExpanderPage.xaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dev/Expander/TestUI/ExpanderPage.xaml b/dev/Expander/TestUI/ExpanderPage.xaml
index 68011add7a..ef0faf184b 100644
--- a/dev/Expander/TestUI/ExpanderPage.xaml
+++ b/dev/Expander/TestUI/ExpanderPage.xaml
@@ -76,7 +76,7 @@
 
             <controls:Expander AutomationProperties.Name="ExpanderStretched" ExpandDirection="Down" IsExpanded="True" Margin="12" HorizontalAlignment="Stretch" HorizontalContentAlignment="Right">
                 <controls:Expander.Header>
-                    <TextBlock HorizontalAlignment="Right" Margin="0,0,0,1">This expander stretches along with its content</TextBlock>
+                    <TextBlock HorizontalAlignment="Right">This expander stretches along with its content</TextBlock>
                 </controls:Expander.Header>
                 <StackPanel HorizontalAlignment="Right">
                     <TextBlock>Header and Content is right aligned</TextBlock>
@@ -85,7 +85,7 @@
 
             <controls:Expander AutomationProperties.Name="ExpanderSetHeight" ExpandDirection="Down" IsExpanded="False" Margin="12" Height="150" MaxWidth="{ThemeResource FlyoutThemeMaxWidth}">
                 <controls:Expander.Header>
-                    <TextBlock Margin="0,0,0,1">This expander sets a fixed height</TextBlock>
+                    <TextBlock>This expander sets a fixed height</TextBlock>
                 </controls:Expander.Header>
                 <ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
                     <TextBlock TextWrapping="Wrap">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec id lacinia tellus. Integer eu mollis leo, ornare ultricies neque. Sed diam lectus, varius sed justo vel, malesuada condimentum lorem. Proin porttitor quis enim a facilisis. Suspendisse vehicula imperdiet egestas. Suspendisse imperdiet, ipsum in commodo cursus, mi nisl volutpat nulla, in interdum mi nulla a nulla. Cras feugiat odio ac eros ullamcorper suscipit. Praesent ultricies ligula eget efficitur tristique. Donec imperdiet ultrices dolor sollicitudin bibendum. In hac habitasse platea dictumst. Fusce vel lacinia purus. Sed tempor est sed suscipit luctus. Aenean laoreet tellus vitae efficitur scelerisque. Sed suscipit risus ac nisl rhoncus hendrerit.</TextBlock>