It can not click when box.ShowAsync().Result;

[StarRiver123]

it seem that loop

[levinit]

Any more description? Do you call it in an override window OnClosing event handler function?

[Swellshinider]

I think i found his problem:

I've setup a simple button in my main window:

<Button
	Width="32"
	Height="32"
	Cursor="Hand"
	HorizontalAlignment="Stretch"
	Click="Button_Click">
</Button>

private void Button_Click(object? sender, RoutedEventArgs e)
{
    var box = MessageBoxManager
      .GetMessageBoxStandard("Caption", "Are you sure you would like to delete appender_replace_page_1?",
          ButtonEnum.YesNo);
    _ = box.ShowAsync().Result; // <- Issue
}

Issue:

When the button is clicked, the application thread gets blocked.

Observed Behavior:

• The message box becomes unresponsive.
• The main window also becomes unclickable.
• The application is effectively frozen.

Using async with await seems to resolve the problem

private async void Button_PlayStopClick(object? sender, RoutedEventArgs e)
{
    var box = MessageBoxManager
      .GetMessageBoxStandard("Caption", "Are you sure you would like to delete appender_replace_page_1?",
          ButtonEnum.YesNo);
    _ = await box.ShowAsync();
}

[CreateLab]

That's typical "feature" of gui frameworks
https://blog.stephencleary.com/2012/07/dont-block-on-async-code.html