private void MoveFocus(ListBox listBox, FocusNavigationDirection direction)
{
var scrollViewer = VisualTreeExtensions.FindVisualChildren <ScrollViewer>(listBox).First();
if (direction == FocusNavigationDirection.First)
{
scrollViewer.ScrollToTop();
}
else
{
scrollViewer.ScrollToBottom();
}
Dispatcher.Invoke(new Action(() => { listBox.MoveFocus(new TraversalRequest(direction)); }),
DispatcherPriority.ContextIdle, null);
}
private void AssociatedObjectOnPreviewKeyDown(object sender, KeyEventArgs keyEventArgs)
{
if (keyEventArgs.Key != Key.Tab)
{
return;
}
var listBox = ((ListBox)sender);
int index;
FocusNavigationDirection direction;
if (Keyboard.Modifiers.HasFlag(ModifierKeys.Shift))
{
index = 0;
direction = FocusNavigationDirection.Last;
}
else
{
index = listBox.Items.Count - 1;
direction = FocusNavigationDirection.First;
}
var focusedItem = ((DependencyObject)Keyboard.FocusedElement).FindParent <ListBoxItem>();
if (focusedItem == null || focusedItem.Content != listBox.Items[index])
{
return;
}
keyEventArgs.Handled = true;
var scrollViewer = VisualTreeExtensions.FindVisualChildren <ScrollViewer>(listBox).First();
if (direction == FocusNavigationDirection.First)
{
scrollViewer.ScrollToTop();
}
else
{
scrollViewer.ScrollToBottom();
}
Dispatcher.Invoke(new Action(() =>
{
listBox.MoveFocus(new TraversalRequest(direction));
}), DispatcherPriority.ContextIdle, null);
}