MediaPlayer，打ze模式，唤醒锁定和前台服务

本文介绍了MediaPlayer，打ze模式，唤醒锁定和前台服务的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我已经阅读了有关Android M中新的打ze"模式的几篇文章，以及Android开发者网站上的文章: developer.android/training/monitoring-device-state/doze-standby.html ，但是前景服务仍然存在问题在手机(Android 6.0.1)上运行.

I have read several posts regarding the new 'Doze' Mode in Android M, also the article on Android developers website : developer.android/training/monitoring-device-state/doze-standby.html yet I still have an issue with a Foreground Service correctly running on a phone (Android 6.0.1).

问题:

我有一个服务，该服务使用MediaPlayer对象处理播放音乐，该服务实现onCompletion和onPrepared MediaPlayer接口.

I have a Service which handles playing music using a MediaPlayer object, the Service Implements onCompletion and onPrepared MediaPlayer interfaces.

伪代码:

public class MusicService extends Service implements MediaPlayer.OnPreparedListener, MediaPlayer.OnCompletionListener, MediaPlayer.OnErrorListener { // Class Variables/Methods etc... @Override public void onPrepared(MediaPlayer mp) { mp.start(); // update notification using startForeground() } @Override public void onCompletion(MediaPlayer mp) { // Go and get another music track in separate thread // (Have used AsyncTask and RX Java/RX Android to test if problem is here - works fine) } @Override public boolean onError(MediaPlayer mp, int what, int extra) { // handleError return false; } }

当手机已插入电源，屏幕处于打开状态或打开了应用程序且屏幕处于打开状态时，该应用程序运行良好.但是，当电话一直处于闲置状态并播放音乐(介于5至40分钟之间)时，一旦调用onCompletion()，服务将无法检索下一个曲目.

The app works well, when the phone is plugged into a power source, or when the screen is on, or app is open and screen is on. However when the phone has been sitting idle and playing music (between 5 - 40mins) the Service fails to retrieve the next track once onCompletion() is called.

该服务已设置并符合以下条件:

• 服务通知从startForeground
开始
• MediaPlayer对象具有部分唤醒锁PARTIAL_WAKE_LOCK
• 该服务在与主应用程序/UI分开的过程中运行
• 所有媒体都使用prepareAsync()(逻辑以获取下一个轨道uri是在后台线程中执行，prepareAsync()仅在主线程中调用)

• The Service Notification is started with startForeground
• The MediaPlayer Object has a partial wakelock PARTIAL_WAKE_LOCK
• The Service runs in a separate process to the main app/UI
• All Media uses prepareAsync() (logic to get the next track uri is performed in background thread, prepareAsync() is called only in the Main thread)

我尝试过的事情:

• 在主线程而不是后台线程中检索下一首歌(在onCompletion调用之后)
• 在onCompletion()中获取一个单独的Partial WakeLock，然后在调用onPrepared()时按住并释放它.
• 其他没什么大不了的事...

我有一个logcat输出，从手机离开时起，在屏幕关闭的状态下保持一段时间不变，然后松开了插头(logcat是在我重新插入并更新日志后获得的)，这说明了问题所在.

I have a logcat output, from when the phone is left, untouched for a period of time with the screen off, and UNPLUGGED (logcat was obtained once I plugged it back in and it updated the log) which demonstrates the problem.

06-15 02:31:39.346 musicplayer:music_service E/MusicService: onPrepared : Tom Petty GH - 11 - You Got Lucky 06-15 02:31:39.548 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:35:15.467 musicplayer:music_service E/MusicService: onCompletion called 06-15 02:35:15.467 musicplayer:music_service D/MusicService: Acquiring wakelock 06-15 02:35:15.514 musicplayer:music_service D/NextActionStrategy: Retrieving song - rx java - Main Ui Thread =false 06-15 02:35:15.870 musicplayer:music_service D/NextActionStrategy: Song Retrieved : Ten Years- Main Ui Thread = true 06-15 02:35:15.950 musicplayer:music_service E/MusicService: onPrepared : Ten Years 06-15 02:35:16.149 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:38:59.002 musicplayer:music_service E/MusicService: onCompletion called 06-15 02:38:59.002 musicplayer:music_service D/MusicService: Acquiring wakelock 06-15 02:38:59.049 musicplayer:music_service D/NextActionStrategy: Retrieving song - rx java - Main Ui Thread =false 06-15 02:38:59.211 musicplayer:music_service D/NextActionStrategy: Song Retrieved : What Am I- Main Ui Thread = true 06-15 02:50:07.642 musicplayer:music_service E/MusicService: onPrepared : What Am I 06-15 02:50:07.976 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:50:22.097 musicplayer:music_service D/MusicService: onStartCommand called : action.PAUSE

例程应为

• 播放曲目
• onCompletion()被称为
• 获取唤醒锁以获取下一首曲目
• PrepareAsync()
• onPrepared调用-使用startForeground开始播放并更新通知

从日志中您可以在02:38:59.xxx看到onCompletion被调用，找到一条轨道，并返回到调用prepareAsync()的主线程，但是在12分钟内没有任何反应，直到我手动唤醒打电话，然后代码会继续，从哪里停止，然后开始播放曲目.

From the logs you can see at 02:38:59.xxx onCompletion is called, a track is found, and returns to the Main thread where prepareAsync() is called, but then nothing happens for 12mins until I manually wake the phone up, and at which point just code continues where is stopped and the track starts playing.

在这种情况下，我不认为其设备可以像我使用的其他音乐应用程序一样正常工作，但是我仅限于在一台真实设备上进行测试:(

I don't believe its the device as other music apps I use work fine in this situation, however I am limited to testing on one real device only :(

如果您有这么远的帮助，请多多关照！任何建议将不胜感激(希望有一个解决方案，而不是我的音乐品味！).

If you've got this far thanks for bearing with me! Any suggestions would be appreciated (hopefully regarding a solution and not my music tastes!).

推荐答案

我只是想让您了解我如何实现startForeground()方法.也许可以帮忙:

I just wanted you to see how I am implementing my startForeground() method. Maybe this can help:

void setUpAsForeground(String text) { mNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE); PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, Main.class), 0); NotificationCompat.Builder noti = new NotificationCompat.Builder(this) .setContentTitle( "My App Title") .setContentText(text) .setSmallIcon(R.drawable.ic_stat_recording) .setStyle(new NotificationCompat.BigTextStyle() .bigText(text)) .setPriority(Notification.PRIORITY_MAX) .setContentIntent(contentIntent) .setOngoing(false); final Notification notification = noti.build(); //mNotificationManager.notify(NOTIFICATION_ID, noti.build()); startForeground(NOTIFICATION_ID, notification); }

在onCreate()中:

@Override public void onCreate() { PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE); PowerManager.WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakelockTag"); wakeLock.acquire(); *********** }