Android 12点击通知操作按钮后如何取消通知（替代BroadcastReceiver方案）

先澄清一个误解 #

Android 12+的通知蹦床限制，只禁止从BroadcastReceiver/Service中启动Activity的行为。如果你的BroadcastReceiver仅仅是用来取消通知，完全不涉及启动Activity，那这种用法是合规的，完全可以继续沿用之前的实现。

方案1：继续使用BroadcastReceiver（仅处理取消通知） #

只要你的BroadcastReceiver里不启动Activity，就不会触发蹦床限制。可以继续用原来的代码，注意给PendingIntent设置符合Android 12+的flag（FLAG_IMMUTABLE或FLAG_MUTABLE，根据是否需要修改Intent决定）：

构建通知Action的PendingIntent时：

Intent cancelIntent = new Intent(context, NotificationBroadcastReceiver.class);
cancelIntent.putExtra("notificationId", notificationId);
PendingIntent pendingCancelIntent = PendingIntent.getBroadcast(
    context,
    0,
    cancelIntent,
    PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE // Android 12+必须加这个flag
);

NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID)
    .setSmallIcon(R.drawable.ic_notification)
    .setContentTitle("通知标题")
    .setContentText("通知内容")
    .addAction(R.drawable.ic_cancel, "取消", pendingCancelIntent);

BroadcastReceiver的代码和你之前的一样（确保不启动Activity）：

private class NotificationBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationManager mNotificationManager = 
            (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        final int NOTIFICATION_ID = intent.getIntExtra("notificationId", 0);
        mNotificationManager.cancel(NOTIFICATION_ID);
    }
}

方案2：在目标Activity中取消通知 #

如果你的通知操作按钮确实需要启动Activity，那可以把通知ID通过Intent传递给Activity，在Activity的生命周期方法里取消通知：

1. 构建指向Activity的PendingIntent时传入notificationId：

Intent activityIntent = new Intent(context, TargetActivity.class);
activityIntent.putExtra("notificationId", notificationId);
PendingIntent pendingActivityIntent = PendingIntent.getActivity(
    context,
    0,
    activityIntent,
    PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE
);

NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID)
    .setSmallIcon(R.drawable.ic_notification)
    .setContentTitle("通知标题")
    .setContentText("通知内容")
    .addAction(R.drawable.ic_open, "打开页面", pendingActivityIntent);

2. 在TargetActivity中取消通知：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_target);
    
    int notificationId = getIntent().getIntExtra("notificationId", 0);
    if (notificationId != 0) {
        NotificationManager notificationManager = 
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.cancel(notificationId);
    }
}

// 如果Activity是singleTop或singleTask模式，还要处理onNewIntent
@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    int notificationId = intent.getIntExtra("notificationId", 0);
    if (notificationId != 0) {
        NotificationManager notificationManager = 
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.cancel(notificationId);
    }
}

方案3：利用通知的自动取消特性（仅适用于点击通知主体的情况） #

如果是点击通知主体（不是操作按钮）要让通知消失，可以直接给NotificationCompat.Builder设置setAutoCancel(true)，这样点击通知主体后系统会自动取消通知：

NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID)
    .setSmallIcon(R.drawable.ic_notification)
    .setContentTitle("通知标题")
    .setContentText("通知内容")
    .setAutoCancel(true) // 点击通知主体自动取消
    .setContentIntent(pendingActivityIntent);

但这个方法对操作按钮的点击无效，操作按钮的点击还是需要手动处理取消。

内容的提问来源于stack exchange，提问作者joghm