startNotificationClickedHandler method
Implementation
@override
Future<void> startNotificationClickedHandler(
NotificationClickedHandler handler,
) async {
// 핸들러 등록
_notificationClickedHandler = handler;
debugPrint('_notificationClickedHandler has been registered');
// 네이티브 메서드 호출
await methodChannel.invokeMethod<void>('startNotificationClickedHandler');
}