ContentDialog without Buttons lets focus shift to background and interact with background

[dbirler]

Describe the bug

I would have expected that if a ContentDialog is shown, no interaction with anything in the background is possible. But this is not what's currently happening. To me it seems that when the ContentDialog has no control that the user can interact with, the focus can "escape" to the background and interact with the controls that are supposed to be "disabled".

To me this is a severe issue, as i use ContentDialog as progress message dialogs and during their showtime the user is not supposed to interact with anything that is in the background of the dialog.

Sample to reproduce: TestContentDialog.zip

Steps to reproduce the bug

1. Launch the test app
2. Click Button "Click Me"
3. Press [TAB] and watch focus shift to "Button1"
4. Press [SPACEBAR] and watch content of "Button1" changing

Expected behavior

No interaction with anything but the ContentDialog is possible while the ContentDialog is open.

Screenshots

TestContentDialog.mp4

NuGet package version

WinUI 3 - Windows App SDK 1.6.1: 1.6.240923002

Windows version

Windows 10 (21H2): Build 19044

Additional context

No response

[github-actions]

Hi I'm an AI powered bot that finds similar issues based off the issue title.

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one. Thank you!

Open similar issues:

• Content Dialog Not Blocking Interactions with the App Window (#5739), similarity score: 0.84

Closed similar issues:

• ContentDialogs buttons are part of tab-navigation even when the dialog is hidden. (#5596), similarity score: 0.81

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[dbirler]

Workaround is to put IsTabStop = true on a control in the ContentDialog like this:

public sealed partial class MainWindow : Window
{
  ContentDialog contentDialog = null;

  public MainWindow()
  {
    this.InitializeComponent();
  }

  private async void myButton_Click(object sender, RoutedEventArgs e)
  {
    myButton.Content = "Clicked";

    TextBlock textBlock = new TextBlock() { Text = "Hello World!", IsTabStop = true };
    textBlock.Tapped += TextBlock_Tapped;

    contentDialog = new ContentDialog();
    contentDialog.Title = "Test";
    contentDialog.Content = textBlock;
    contentDialog.XamlRoot = this.Content.XamlRoot;

    await contentDialog.ShowAsync();
  }

  private void TextBlock_Tapped(object sender, TappedRoutedEventArgs e)
  {
    contentDialog.Hide();
  }

  private void button1_Click(object sender, RoutedEventArgs e)
  {
    button1.Content = "Button 1 Clicked";
  }

  private void button2_Click(object sender, RoutedEventArgs e)
  {
    button2.Content = "Button 2 Clicked";
  }
}

[dbirler]

Closing this as it is possibly a duplicate of #5739 but this should really be investigated and fixed at the framework level, as imho this is a critical bug.