How to capture Ctrl + Tab and Ctrl + Shift + Tab in WPF?

What KeyDown handler did you have? The code below works for me. The one that gives me trouble is: Alt + Tab, but you didn’t ask for that 😀

public Window1()
{
   InitializeComponent();
   AddHandler(Keyboard.KeyDownEvent, (KeyEventHandler)HandleKeyDownEvent);
}

private void HandleKeyDownEvent(object sender, KeyEventArgs e)
{
   if (e.Key == Key.Tab && (Keyboard.Modifiers & (ModifierKeys.Control | ModifierKeys.Shift)) == (ModifierKeys.Control | ModifierKeys.Shift))
   {
      MessageBox.Show("CTRL + SHIFT + TAB trapped");
   }

   if (e.Key == Key.Tab && (Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
   {
      MessageBox.Show("CTRL + TAB trapped");
   }
}