问如何更新Android前台服务的通知文本？
EN

Stack Overflow用户

提问于 2011-04-03 07:41:55

回答 5查看 71.2K关注 0票数 152

我有一个Android的前台服务设置。我想要更新通知文本。我正在创建如下所示的服务。

如何更新在此前台服务中设置的通知文本？更新通知的最佳实践是什么？任何示例代码都将不胜感激。

public class NotificationService extends Service {

    private static final int ONGOING_NOTIFICATION = 1;

    private Notification notification;

    @Override
    public void onCreate() {
        super.onCreate();

        this.notification = new Notification(R.drawable.statusbar, getText(R.string.app_name), System.currentTimeMillis());
        Intent notificationIntent = new Intent(this, AbList.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
        this.notification.setLatestEventInfo(this, getText(R.string.app_name), "Update This Text", pendingIntent);

        startForeground(ONGOING_NOTIFICATION, this.notification);

    }

我在我的主活动中创建服务，如下所示：

    // Start Notification Service
    Intent serviceIntent = new Intent(this, NotificationService.class);
    startService(serviceIntent);

service

notifications

foreground

android

回答 5

Stack Overflow用户

回答已采纳

发布于 2011-04-03 11:52:49

我认为使用相同的惟一ID和使用新信息的Notification再次调用startForeground()是可行的，尽管我还没有尝试过这种情况。

更新:根据评论，您应该使用NotifcationManager更新通知，您的服务将继续停留在前台模式。看看下面的答案。

票数 68

Stack Overflow用户

发布于 2013-11-22 10:31:11

当您想要通过startForeground()更新通知集时，只需构建一个新的通知，然后使用NotificationManager来通知它。

关键点是使用相同的通知id。

我没有测试重复调用startForeground()来更新通知的场景，但我认为使用NotificationManager.notify会更好。

更新通知不会将服务从前台状态移除(这只能通过调用stopForground来完成)；

示例：

private static final int NOTIF_ID=1;

@Override
public void onCreate (){
    this.startForeground();
}

private void startForeground() {
    startForeground(NOTIF_ID, getMyActivityNotification(""));
}

private Notification getMyActivityNotification(String text){
    // The PendingIntent to launch our activity if the user selects
    // this notification
    CharSequence title = getText(R.string.title_activity);
    PendingIntent contentIntent = PendingIntent.getActivity(this,
            0, new Intent(this, MyActivity.class), 0);

    return new Notification.Builder(this)
            .setContentTitle(title)
            .setContentText(text)
            .setSmallIcon(R.drawable.ic_launcher_b3)
            .setContentIntent(contentIntent).getNotification();     
}

/**
 * This is the method that can be called to update the Notification
 */
private void updateNotification() {
    String text = "Some text that will update the notification";

    Notification notification = getMyActivityNotification(text);

    NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mNotificationManager.notify(NOTIF_ID, notification);
}

documentation状态

要设置通知以便可以更新，请通过调用NotificationManager.notify()使用通知ID发出通知。要在发出通知后更新该通知，请更新或创建一个NotificationCompat.Builder对象，从该对象构建一个Notification对象，并使用您之前使用的相同ID发出Notification。如果先前的通知仍然可见，系统将根据Notification对象的内容对其进行更新。如果先前的通知已被驳回，则会创建一个新的通知。

票数 256

Stack Overflow用户

发布于 2018-03-12 14:48:35

改进了安卓8.0+中的Luca Manzo answer，当更新通知时，它将发出声音并显示为平视。

为了防止出现这种情况，您需要添加setOnlyAlertOnce(true)

所以代码是：

private static final int NOTIF_ID=1;

@Override
public void onCreate(){
        this.startForeground();
}

private void startForeground(){
        startForeground(NOTIF_ID,getMyActivityNotification(""));
}

private Notification getMyActivityNotification(String text){
        if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.O){
        ((NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE)).createNotificationChannel(
        NotificationChannel("timer_notification","Timer Notification",NotificationManager.IMPORTANCE_HIGH))
}

        // The PendingIntent to launch our activity if the user selects
        // this notification
        PendingIntent contentIntent=PendingIntent.getActivity(this,
        0,new Intent(this,MyActivity.class),0);

        return new NotificationCompat.Builder(this,"my_channel_01")
        .setContentTitle("some title")
        .setContentText(text)
        .setOnlyAlertOnce(true) // so when data is updated don't make sound and alert in android 8.0+
        .setOngoing(true)
        .setSmallIcon(R.drawable.ic_launcher_b3)
        .setContentIntent(contentIntent)
        .build();
}

/**
 * This is the method that can be called to update the Notification
 */
private void updateNotification(){
        String text="Some text that will update the notification";

        Notification notification=getMyActivityNotification(text);

        NotificationManager mNotificationManager=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        mNotificationManager.notify(NOTIF_ID,notification);
}