好久沒寫文章，今天遇到一個新需求，app正在通話過程切換到後臺，點選通知欄的時候 回到通話介面。

直接上程式碼吧

首先是實現通知的程式碼

NotificationCompat.Builder notificationBuild =null;
    int NOTIFY_ID = 100;
    NotificationManager mNotificationManager;
    boolean isHasNotification = false;
    android.app.Notification notification;
    /**
     * 顯示通知欄
     */
 

    public void showNotification(String title,String content){
        if (mNotificationManager == null&&!isHasNotification){
            Intent deleteIntent = new Intent(this, NotificationTipsReceiver.class);
            notificationBuild = new NotificationCompat.Builder(this);
            notificationBuild.setAutoCancel(false
 
);//設定能手動取消
            notificationBuild.setOngoing(true);//設定不能取消
            notificationBuild.setContentTitle(title);
            notificationBuild.setSmallIcon(R.mipmap.icon);//設定圖示
            notificationBuild.setTicker("小尾巴 正在接單中");
            notificationBuild.setDefaults(android.app.Notification.DEFAULT_ALL);
            notificationBuild.setPriority(android.app.Notification.PRIORITY_MAX);
            PendingIntent pendingIntent = PendingIntent.getBroadcast(this
 
,
                    0, deleteIntent, 0);
            notificationBuild.setContentIntent(pendingIntent);
            mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        }
        notification = notificationBuild.build();
        mNotificationManager.notify(NOTIFY_ID, notification);
        isHasNotification = true;
    }

下面是通知點選處理類

public class NotificationTipsReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        //判斷app程序是否存活
        boolean isApplive = SystemUtil.isAppAlive(context, "com.iol8.te.tr");
        Intent  dialogIntent = new Intent(context, DialogueActivity.class);
dialogIntent.setFlags(Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED|Intent.FLAG_ACTIVITY_NEW_TASK);//注意這裡是關鍵  經過測試Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED也可以用Intent.FLAG_ACTIVITY_SINGLE_TOP  也可以做到   具體區別沒有去深入測試
        if (isApplive) {
            if (WYIMManager.isDialogue) {
                if (!SystemUtil.isAppRunningForeground(context)){//app在後臺執行
                    context.startActivity(dialogIntent);
                }
                return;
            }

        }
    }
}

另外附上一個Intent的flag 啟動介紹（感謝這位大神的分享）
Android Intent flag 介紹