Context.startForegroundService() did not then call Service.startForeground()

从 Android 中service 详解 和Android service 启动篇之 startForegroundService 中我们知道在android 8.0 禁止启动后台服务。提出通过startForegroundService() 启动前台服务。但是必须要配合在service 中调用Service.startForeground()，不然就会出现ANR 或者crash。

ANR log 如下：

11-06 02:01:59.616  3877  3893 E ActivityManager: ANR in com.shift.phonemanager.permission.accesslog
11-06 02:01:59.616  3877  3893 E ActivityManager: PID: 1369
11-06 02:01:59.616  3877  3893 E ActivityManager: Reason: Context.startForegroundService() did not then call Service.startForeground()
11-06 02:01:59.616  3877  3893 E ActivityManager: Load: 0.0 / 0.0 / 0.0
11-06 02:01:59.616  3877  3893 E ActivityManager: CPU usage from 7945ms to 0ms ago (2007-11-06 02:01:51.418 to 2007-11-06 02:01:59.363):
11-06 02:01:59.616  3877  3893 E ActivityManager:   60% 3877/system_server: 35% user + 25% kernel / faults: 3744 minor 6 major
11-06 02:01:59.616  3877  3893 E ActivityManager:   25% 1042/com.android.launcher3: 20% user + 4.9% kernel / faults: 11190 minor 9 major
11-06 02:01:59.616  3877  3893 E ActivityManager:   18% 1149/android.process.media: 13% user + 5.3% kernel / faults: 6130 minor
11-06 02:01:59.616  3877  3893 E ActivityManager:   15% 1420/adbd: 3.6% user + 11% kernel / faults: 5074 minor
11-06 02:01:59.616  3877  3893 E ActivityManager:   9.7% 255/logd: 2.7% user + 6.9% kernel / faults: 5 minor
11-06 02:01:59.616  3877  3893 E ActivityManager:   9.2% 3814/surfaceflinger: 4.4% user + 4.8% kernel / faults: 658 minor

crash log 如下：

--------- beginning of crash
11-06 02:06:05.307  3106  3106 E AndroidRuntime: FATAL EXCEPTION: main
11-06 02:06:05.307  3106  3106 E AndroidRuntime: Process: com.shift.phonemanager.permission.accesslog, PID: 3106
11-06 02:06:05.307  3106  3106 E AndroidRuntime: android.app.RemoteServiceException: Context.startForegroundService() did not then call Service.startForeground()
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1771)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at android.os.Handler.dispatchMessage(Handler.java:106)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:164)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:6518)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
11-06 02:06:05.307  3106  3106 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
11-06 02:06:05.320  3118  3118 D ExtensionsFactory: No custom extensions.

实例：

    private void showNotification() {
        // In this sample, we'll use the same text for the ticker and the expanded notification
        CharSequence text = getText(R.string.local_service_started);
 
        // The PendingIntent to launch our activity if the user selects this notification
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
                new Intent(this, LocalServiceActivities.Controller.class), 0);
 
        // Set the info for the views that show in the notification panel.
        Notification notification = new Notification.Builder(this)
                .setSmallIcon(R.drawable.stat_sample)  // the status icon
                .setTicker(text)  // the status text
                .setWhen(System.currentTimeMillis())  // the time stamp
                .setContentTitle(getText(R.string.local_service_label))  // the label of the entry
                .setContentText(text)  // the contents of the entry
                .setContentIntent(contentIntent)  // The intent to send when the entry is clicked
                .build();
 
        // Send the notification.
        mNM.notify(NOTIFICATION, notification);
    }

实例：

    private void setForegroundNotification() {
        NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
 
        String channelId = "access_log_channel";
        NotificationChannel channel = new NotificationChannel(channelId, "channel_1",
                NotificationManager.IMPORTANCE_DEFAULT);
 
        nm.createNotificationChannel(channel);
 
        Notification notification = new Notification.Builder(this).setChannelId(channelId)
                .setSmallIcon(R.drawable.ic_launcher)
                .setContentTitle(getString(R.string.permission_access_log_title))
                .build();
        startForeground(1, notification);
    }

参考：

https://developer.android.com/about/versions/oreo/background

https://developer.android.com/reference/android/app/Service