“Only a single ContentDialog can be open at any time.” error while opening another contentdialog

Question

I am using Windows.UI.Xaml.Controls.ContentDialog to show a confirmation. And based on the response from the first dialog I would (or would not) show another di

Answer 1

William Bradley's approach above is good. Just to polish it up a bit, here is an extension method to submit and await the showing of a content dialog; the dialog will be shown after all the other content dialogs that have already been submitted. Note: by the time the user clicks through earlier backlogged dialogs you may no longer want to show the dialog that you have submitted; to indicate this you may pass a predicate that will be tested after the other dialogs have been dismissed.

static public class ContentDialogExtensions
{
    static public async Task EnqueueAndShowIfAsync( this ContentDialog contentDialog, Func predicate = null)
    {
        TaskCompletionSource currentDialogCompletion = new TaskCompletionSource();
        TaskCompletionSource previousDialogCompletion = null;

        // No locking needed since we are always on the UI thread.
        if (!CoreApplication.MainView.CoreWindow.Dispatcher.HasThreadAccess) { throw new NotSupportedException("Can only show dialog from UI thread."); }
        previousDialogCompletion = ContentDialogExtensions.PreviousDialogCompletion;
        ContentDialogExtensions.PreviousDialogCompletion = currentDialogCompletion;

        if (previousDialogCompletion != null) {
            await previousDialogCompletion.Task;
        }
        var whichButtonWasPressed = ContentDialogResult.None;
        if (predicate == null || predicate()) {
            whichButtonWasPressed = await contentDialog.ShowAsync();
        }
        currentDialogCompletion.SetResult(null);
        return whichButtonWasPressed;
    }

    static private TaskCompletionSource PreviousDialogCompletion = null;
}

Another way might be to use a SemaphoreSlim(1,1).