heads-up notification

MainActivity.java

Intent notificationIntent = new Intent(MainActivity.this,MainActivity.class);
                notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                PendingIntent contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);


                Notification notification = new Notification.Builder(MainActivity.this)
                        .setSmallIcon(R.drawable.ic_launcher)
                        .setFullScreenIntent(contentIntent, true)
                        .addAction(R.drawable.ic_launcher,"add",contentIntent)
                        .build();
                final int notifyID = 1; // 通知的識別號碼
                final NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); // 取得系統的通知服務
                notificationManager.notify(notifyID, notification);