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
}