Question

我想更新通知数据，但我发现的唯一方法是启动一个具有相同ID的新数据。

问题是，如果取消原作，我不想再提出新的。有没有办法判断通知是否可见或取消？或者只有在通知存在时更新通知的方法？

Answer 1

这就是我解决它的方法：

    private boolean isNotificationVisible() {
    Intent notificationIntent = new Intent(context, MainActivity.class);
    PendingIntent test = PendingIntent.getActivity(context, MY_ID, notificationIntent, PendingIntent.FLAG_NO_CREATE);
    return test != null;
}

这是我生成通知的方式：

    /**
 * Issues a notification to inform the user that server has sent a message.
 */
private void generateNotification(String text) {

    int icon = R.drawable.notifiaction_icon;
    long when = System.currentTimeMillis();
    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    Notification notification = new Notification(icon, text, when);
    String title = context.getString(R.string.app_name);
    Intent notificationIntent = new Intent(context, MainActivity.class);

    // set intent so it does not start a new activity
    //notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
    PendingIntent intent = PendingIntent.getActivity(context, MY_ID, notificationIntent, 0);
    notification.setLatestEventInfo(context, title, text, intent);

    notification.flags |= Notification.FLAG_AUTO_CANCEL; //PendingIntent.FLAG_ONE_SHOT

    notificationManager.notify(MY_ID, notification);
}

Answer 2

如果您使用API >= 23，可以使用此方法获取有效通知：

NotificationManager mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
StatusBarNotification[] notifications = mNotificationManager.getActiveNotifications();
for (StatusBarNotification notification : notifications) {
  if (notification.getId() == 100) {
    // Do something.
  }
}

Answer 3

我认为您可以使用Notification类的deleteIntent。

我记得在我的一个应用程序中，当取消通知或清除通知托盘时，我使用use来触发广播（自定义广播）。

Answer 4

以下deleteIntent的替代方案在我自己的应用程序中证明是有益的：

基本上，您使用启动IntentService（或任何其他服务）的通知创建意图，并在onHandleIntent中设置一个标记，指示通知是否有效。
您可以设置在用户点按通知（contentIntent）和/或用户从列表中清除通知（deleteIntent）时触发此意图。

为了说明这一点，这是我在自己的应用程序中所做的。在构建通知时，我设置了

Intent intent = new Intent(this, CleanupIntentService.class);
Notification n = NotificationCompat.Builder(context).setContentIntent(
        PendingIntent.getActivity(this, 0, intent, 0)).build();

点击通知后，我的CleanupIntentService会启动，设置一个标志（在创建通知的服务中）：

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    super.onCreate(); // If removed, onHandleIntent is not called
    return super.onStartCommand(intent, flags, startId);
}


@Override
protected void onHandleIntent(Intent intent) {
    OtherService.setNotificationFlag(false);
}

Answer 5

在我的情况下，我想先检查一个通知是否已显示，然后再显示另一个。事实证明，有一种简单的方法可以执行此操作，而无需侦听.setAutoCancel(true)上的NotificationManagerCompat.Builder删除或取消通知的时间。

 private val NOTIF_ID = 80085
 private val CHANNEL_ID = "com.package.name.ClassName.WhatNotifycationDoes"  
 private lateinit var mNotificationManagerCompat: NotificationManagerCompat
 private lateinit var mNotificationManager: NotificationManager // this is for creating Notification Channel in newer APIs

override fun onCreate() {
    super.onCreate()

    mNotificationManagerCompat = NotificationManagerCompat.from(this)

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
       mNotificationManager = getSystemService(NotificationManager::class.java)

    showNotification()
    startWatching()
}

private fun showNotification() {
        val contentIntent = Intent(this, MainActivity::class.java)
                .apply { flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK }
        val contentPendingIntent = PendingIntent.getActivity(this, 1, contentIntent, 0)

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        val name = getString(R.string.app_name)
        val importance = NotificationManager.IMPORTANCE_HIGH
        val channel = NotificationChannel(CHANNEL_ID, name, importance)
        channel.description = getString(R.string.your_custom_description)
        mNotificationManager.createNotificationChannel(channel)
    }

    val mNewStatusNotificationBuilder = NotificationCompat.from(this)
    mNewStatusNotificationBuilder = NotificationCompat.Builder(this, CHANNEL_ID)
            .setContentTitle(getString(R.string.app_name))
            .setContentText(getString(R.string.simple_text))
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .setContentIntent(contentPendingIntent)
            .setAutoCancel(true) // This dismisses the Notification when it is clicked
            .setOnlyAlertOnce(true) //this is very important, it pops up the notification only once. Subsequent notify updates are muted. unless it is loaded again    

    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP)
        mNewStatusNotificationBuilder.setSmallIcon(R.drawable.ic_notification)

    notification = mNewStatusNotificationBuilder.build()

    mNotificationManagerCompat.notify(NOTIF_ID, notification)
}

Answer 6

您可以在Kotlin中进行以下检查：

  val mNotificationManager: NotificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    val notifications: Array<StatusBarNotification> = mNotificationManager.activeNotifications

    if(notifications.isNotEmpty())
    {
      //you don't have notifications 
    }
    else
    {
      //you have notifications 
    }

是否可以检查通知是否可见或已取消？

6 个答案: