Events

Class handlers

In WPF, class handlers for events can be added by calling EventManager.RegisterClassHandler. An example of registering a class handler in WPF might be:

WPF

static MyControl()
{
    EventManager.RegisterClassHandler(typeof(MyControl), MyEvent, HandleMyEvent));
}

private static void HandleMyEvent(object sender, RoutedEventArgs e)
{
}

Avalonia

static MyControl()
{
    MyEvent.AddClassHandler<MyControl>((x, e) => x.HandleMyEvent(e));
}

private void HandleMyEvent(RoutedEventArgs e)
{
}

Notice that in WPF you have to add the class handler as a static method, whereas in Avalonia the class handler is not static: the notification is automatically directed to the correct instance. The sender parameter typical of event handlers is not necessary in this case and everything remains strongly typed.

Tunnelling events

Avalonia has tunnelling events but they're not exposed via separate Preview CLR event handlers. To subscribe to a tunnelling event you must call AddHandler with RoutingStrategies.Tunnel:

target.AddHandler(InputElement.KeyDownEvent, OnPreviewKeyDown, RoutingStrategies.Tunnel);

void OnPreviewKeyDown(object sender, KeyEventArgs e)
{
    // Handler code
}

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