/// <summary>Call this method in Loaded event as the event will be automatically
/// deregistered when the FrameworkElement has been unloaded. </summary>
public static void RegisterBackKey(Page page)
{
var callback = new TypedEventHandler <CoreDispatcher, AcceleratorKeyEventArgs>(
delegate(CoreDispatcher sender, AcceleratorKeyEventArgs args)
{
if (!args.Handled && args.VirtualKey == VirtualKey.Back &&
(args.EventType == CoreAcceleratorKeyEventType.KeyDown ||
args.EventType == CoreAcceleratorKeyEventType.SystemKeyDown))
{
var element = FocusManager.GetFocusedElement();
if (element is FrameworkElement && PopupHelper.IsInPopup((FrameworkElement)element))
{
return;
}
if (element is TextBox || element is PasswordBox || element is WebView)
{
return;
}
if (page.Frame.CanGoBack)
{
args.Handled = true;
page.Frame.GoBack();
}
}
});
page.Dispatcher.AcceleratorKeyActivated += callback;
SingleEvent.RegisterEvent(page,
(p, h) => p.Unloaded += h,
(p, h) => p.Unloaded -= h,
(o, a) => { page.Dispatcher.AcceleratorKeyActivated -= callback; });
}
/// <summary>Call this method in Loaded event as the event will be automatically
/// deregistered when the FrameworkElement has been unloaded. </summary>
/// <param name="page">The page. </param>
/// <param name="handler">The event handler. </param>
public static void RegisterAcceleratorKeyActivated(FrameworkElement page, TypedEventHandler <CoreDispatcher, AcceleratorKeyEventArgs> handler)
{
page.Dispatcher.AcceleratorKeyActivated += handler;
SingleEvent.RegisterEvent(page, (p, h) => p.Unloaded += h, (p, h) => p.Unloaded -= h, (o, a) =>
{
page.Dispatcher.AcceleratorKeyActivated -= handler;
});
}