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
}
Avalonia XPF - Cross-Platform WPF