Question

I’m creating a WPF application containing a “Main-Content” – Layer containing a TabControl and a “Dialog” – Layer containing an ItemsControl.

The XAML looks like this:

<Grid>
  <TabControl>
    ..Some Tabs
  </TabControl>

  <ItemsControl>
      <ContentControl Content={Binding Dialog1Property} />
      <ContentControl Content={Binding Dialog2Property} />
  </ItemsControl>
</Grid>

Usually “Dialog1Property” and “Dialog2Property” are null which means the ItemsControl is invisible. Whenever I assign a Control to one of them, it is shown in front of the TabControl which is exactly what I want. If I assign a gray Rectangle with an opacity of 0.7 to one of the Dialog – Properties it creates a Gray overlay.

If I click on the Tab, which is slightly visible through the overlay, nothing happens – the Rectangle blocks Mouse Events. It is, however, still possible to focus the TabControl behind the overlay using the Tab-Key and therefore it is also possible to switch tabs even though a Dialog is shown.

Is there an easy way to tell the rectangle to somehow block key events as it allready does with Mouseclicks?

Regards
BBRain

Answer 1

Yes, on your Rectangle, subscribe to the event PreviewKeyDown.

<Rectangle Opacity="0.7" Fill="Green" PreviewKeyDown="Rectangle_PreviewKeyDown" />

In its handler, simply set e.Handled = true;

private void Rectangle_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            e.Handled = true;
        }

Since routed events prefixed with “Preview…” are tunneling, the elements under your rectangle won’t recieve the input.