Set a GroupName when creating new WinUI RadioButtons

src/Controls/tests/DeviceTests/Elements/RadioButton/RadioButtonTests.Windows.cs

@@ -0,0 +1,13 @@
+using Microsoft.Maui.Handlers;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	public partial class RadioButtonTests
+	{
+		UI.Xaml.Controls.RadioButton GetNativeRadioButton(RadioButtonHandler radioButtonHandler) =>
+			radioButtonHandler.PlatformView;
+
+		bool GetNativeIsChecked(RadioButtonHandler radioButtonHandler) =>
+			GetNativeRadioButton(radioButtonHandler).IsChecked ?? false;
+	}
+}

src/Controls/tests/DeviceTests/Elements/RadioButton/RadioButtonTests.cs

@@ -0,0 +1,44 @@
+#if WINDOWS
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Handlers;
+using Xunit;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	[Category(TestCategory.RadioButton)]
+	public partial class RadioButtonTests : ControlsHandlerTestBase
+	{
+		[Theory(DisplayName = "IsChecked Initializes Correctly")]
+		[InlineData(false)]
+		[InlineData(true)]
+		public async Task IsCheckedInitializesCorrectly(bool isChecked)
+		{
+			bool xplatIsChecked = isChecked;
+			var radioButton = new RadioButton() { IsChecked = xplatIsChecked };
+			bool expectedValue = isChecked;
+			var layoutFirst = new VerticalStackLayout();
+			var rdFirst = new RadioButton { GroupName = "FirstGroup", IsChecked = xplatIsChecked };
+			layoutFirst.Add(rdFirst);
+			layoutFirst.Add(new RadioButton { GroupName = "FirstGroup" });
+			layoutFirst.Add(new RadioButton { GroupName = "FirstGroup" });
+			var layoutSecond = new VerticalStackLayout();
+			layoutSecond.Add(new RadioButton { GroupName = "SecondGroup" });
+			var rdSecond = new RadioButton { GroupName = "SecondGroup", IsChecked = xplatIsChecked };
+			layoutSecond.Add(rdSecond);
+			layoutSecond.Add(new RadioButton { GroupName = "SecondGroup" });
+			var layout = new VerticalStackLayout
+			{
+				layoutFirst,
+				layoutSecond
+			};
+			var valuesFirst = await GetValueAsync(rdFirst, (handler) => { return new { ViewValue = rdFirst.IsChecked, PlatformViewValue = GetNativeIsChecked(handler as RadioButtonHandler) }; });
+			var valuesSecond = await GetValueAsync(rdSecond, (handler) => { return new { ViewValue = rdSecond.IsChecked, PlatformViewValue = GetNativeIsChecked(handler as RadioButtonHandler) }; });
+			Assert.Equal(xplatIsChecked, valuesFirst.ViewValue);
+			Assert.Equal(expectedValue, valuesFirst.PlatformViewValue);
+			Assert.Equal(xplatIsChecked, valuesSecond.ViewValue);
+			Assert.Equal(expectedValue, valuesSecond.PlatformViewValue);
+		}
+	}
+}
+#endif

src/Controls/tests/DeviceTests/TestCategory.cs

@@ -30,6 +30,7 @@ public static class TestCategory
 		public const string NavigationPage = "NavigationPage";
 		public const string Page = "Page";
 		public const string Picker = "Picker";
+		public const string RadioButton = "RadioButton";
 		public const string ScrollView = "ScrollView";
 		public const string SearchBar = "SearchBar";
 		public const string Shell = "Shell";

src/Core/src/Handlers/RadioButton/RadioButtonHandler.Windows.cs

@@ -1,11 +1,16 @@
-using Microsoft.UI.Xaml;
+using System;
+using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 
 namespace Microsoft.Maui.Handlers
 {
 	public partial class RadioButtonHandler : ViewHandler<IRadioButton, RadioButton>
 	{
-		protected override RadioButton CreatePlatformView() => new RadioButton();
+		protected override RadioButton CreatePlatformView()
+		{
+			// Note: We set a random GUID as the GroupName as part of the work-around in https://github.com/dotnet/maui/issues/11418
+			return new RadioButton() { GroupName = Guid.NewGuid().ToString() };
+		}
 
 		protected override void ConnectHandler(RadioButton platformView)
 		{