在任务管理器中无法关闭烤面包机窗口

Question

I use a toaster window , this is the main part of the XAML:

    <Grid.Triggers>
        <EventTrigger RoutedEvent="FrameworkElement.Loaded">
            <BeginStoryboard>
                <Storyboard Completed="Storyboard_Completed">
                    <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleY)" Duration="0:0:10" Completed="DoubleAnimationCompleted">
                        <SplineDoubleKeyFrame KeyTime="0:0:0" Value="0"/>
                        <SplineDoubleKeyFrame KeyTime="0:0:0.5" Value="1"/>
                    </DoubleAnimationUsingKeyFrames>
                    <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)">
                        <SplineDoubleKeyFrame KeyTime="0:0:2" Value="1"/>
                        <SplineDoubleKeyFrame KeyTime="0:0:12" Value="0"/>
                    </DoubleAnimationUsingKeyFrames>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>

Basically it's called with a Show method like this:

    public new void Show()
    {
        this.Topmost = true;
        base.Show();

        this.Owner = System.Windows.Application.Current.MainWindow;
        this.Closed += this.NotificationWindowClosed;
        var workingArea = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea;

        this.Left = workingArea.Right - this.ActualWidth;
        double top = workingArea.Bottom - this.ActualHeight;
        foreach (Window window in System.Windows.Application.Current.Windows)
        {
            string windowName = window.GetType().Name;

            if (windowName.Equals("NotificationWindow") && window != this)
            {
                window.Topmost = true;
                top = window.Top - window.ActualHeight;
            }
        }

        this.Top = top;
    }

The problem is that the Notifications popup remain as a subwindow in the Task Manager. Every time a toaster windows opens (and closes again) an entry is added. In the XAML I already added Completed="DoubleAnimationCompleted" and (following another post in Stackoverflow) a Storyboard Completed="Storyboard_Completed">. Both methods are called and exectute this.Close() but the popups do not diasappear from the taskbar. So this.Close (in whatever way called) seems not to clear these entries.

What can I do to change that?

Answer 1

I finally found the answer from a sample posted by "CrashproofCode" in this WPF 'Toaster' Popup - How to close? . After comparing his code to mine I found 2 differences which caused my code to remain in the taskbar:

WindowStyle="None" AllowsTransparency="True" Background="Transparent" Closing="Window_Closing"

The Window_Closing was called and apparently caused the problem:

private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
    if (!closeCompleted)
    {
        e.Cancel = true;
    }
}

He also had in his XAML:

ShowInTaskbar="False"

and that alone is sufficient to prevent that too.