START_STICKY，前台 Android 服务会在没有通知的情况下消失 [英] START_STICKY, foreground Android service goes away without notice

问题描述

我在我的新应用程序中启动了一项服务.该服务是前台的，带有一个通知.当它在 AVD 2.1 API Level 7 中运行时，一切正常.但是当它在运行 Gingerbread 的三星 Galaxy Tab 上运行时，该服务将启动(图标和应用程序名称出现在通知区域的顶部)，但几秒钟后，该服务消失.我可以看到的日志中的最后一个条目与我的应用程序相关联，是我的 Log.d("Taglines","Returning with " + START_STICKY) 的结果，它紧跟在 "return START_STICKY ;" 之前在我的服务的 onStartCommand 覆盖中，如下所示:

I have started a service in my new application. The service is foregrounded, with a Notification. When this is run in the AVD 2.1 API Level 7, all works fine. But when it's run on a Samsung Galaxy Tab running Gingerbread, the service will start (the icon and app name appear at the top of the notification area), but after a few seconds, the service disappears. The last entry in the Log that I can see is associated with my App, is the result of my Log.d("Taglines","Returning with " + START_STICKY), which immediately precedes "return START_STICKY ;" in my Service's onStartCommand override, as follows:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    int rc ;
    Log.d("Taglines","onStartCommand()");
    Toast.makeText(this, "Starting service TagsManager", Toast.LENGTH_SHORT).show();
    Log.d("Taglines","Calling super.onStartCommand()");
    rc = super.onStartCommand(intent,flags,startId);
    Log.d("Taglines","super.onStartCommand return code was " + rc);
    createNotification(INITIAL_NOTIFICATION_TEXT);
    Log.d("Taglines","Returning with " + START_STICKY);
    return START_STICKY ;
}

通知设置如下:

void createNotification(String text) {

    Log.d("Taglines","createNotification called");
    if (mNotificationManager == null) {
        // Get a reference to the Notification Manager
        String ns = Context.NOTIFICATION_SERVICE;
        mNotificationManager = (NotificationManager) getSystemService(ns);
        Log.d("Taglines","Obtained reference to Notification Manager");
    }

    // Instantiate the Notification
    int icon = R.drawable.ic_notification;
    CharSequence tickerText = "Taglines";
    long when = System.currentTimeMillis();

    notification = new Notification(icon, tickerText, when);

    // Define Notification's expanded message and intent
    Log.d("Taglines","createNotificacion() .. getApplicationContext");
    context = getApplicationContext();
    contentText = text;
    // notificationIntent = new Intent(this, TagsOverview.class);
    notificationIntent = new Intent(this, TagsServiceMenu.class);
    contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);

    notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);

    // Pass the Notification to the NotificationManager: 
    Log.d("Taglines","createNotificacion() ... passing notification");
    mNotificationManager.notify(NOTIFICATION_ID, notification);
    Log.d("Taglines","Starting foreground");
    startForeground(NOTIFICATION_ID, notification);
    Log.d("Taglines","Started");
}

这是服务启动时adb logcat"的结果:

This is the result from "adb logcat" when the service is started:

D/Taglines(21863): Starting service
D/Taglines(21863): TagsManager(nullary) completed
D/Taglines(21863): onStartCommand()
D/Taglines(21863): Calling super.onStartCommand()
D/Taglines(21863): super.onStartCommand eturn code was 2
D/Taglines(21863): createNotification called
D/Taglines(21863): Obtained reference to Notification Manager
D/Taglines(21863): createNotificacion() .. getApplicationContext
D/Taglines(21863): createNotificacion() ... passing notification
D/Taglines(21863): Starting foreground
D/Taglines(21863): Started
D/Taglines(21863): Returning with 1

在那之后，没有什么特别的(PID 21863 没有任何东西).只是一堆:

After that, nothing special (nothing at all from PID 21863). Just a bunch of:

D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
W/InputManagerService(  302): Window already focused, ignoring focus gain of:         com.android.internal.view.IInputMethodClient$Stub$Proxy@40bc06e8
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false
D/KeyguardViewMediator(  302): setHidden false

我认为在这种情况下不需要它，但这是 AndroidManifest.xml 的相关部分:

I don't think it's needed in this case, but here's the relevant portion of the AndroidManifest.xml:

    <service android:name=".TagsManager"
             android:exported="false">
    </service>

我可能哪里出错了?我还可以提供哪些其他信息?

Where might I have gone wrong? What other information can I provide?

推荐答案

一些事情:

1. 去掉mNotificationManager.notify(NOTIFICATION_ID, notification);.startForeground() 为您显示通知图标.

1. Get rid of the mNotificationManager.notify(NOTIFICATION_ID, notification);. startForeground() displays the notification icon for you.

前台 Service 仍然可以被杀死，只是不太可能.

Foreground Services can still be killed, they're just less likely to be.

在 2.3 中有一个错误(不确定它是否已修复)，当 Service 被杀死并重新启动时，它的 onStartCommand() 将不会又叫.相反，您将不得不在 onCreate() 中进行任何设置.

There's a bug in 2.3 (not sure if it was fixed yet) where when a Service is killed and restarted, its onStartCommand() will NOT be called again. Instead you're going to have to do any setting up in onCreate().

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