java - 服务在 android 中泄露了 IntentReceiver

Question

我正在制作一个安卓应用。我正在制作一项服务，该服务在用户选中 checkbox 时一直在后台运行，当用户 unckeck 时它应该停止。所以当我选中该框并且它还显示“服务启动” toast 时它确实有效，但是当我取消选中 复选框时它会显示显示“服务已停止”的 toast 但是它不会停止播放服务启动时开始的声音。停止该声音的唯一方法是关闭我的手机，然后再打开它。

这是我用于启动和停止服务的 java 代码

public int onStartCommand(Intent intent, int flags, int startId) {
    Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();

    this.registerReceiver(this.batteryInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

    return START_STICKY;
}
public void onDestroy() {
    super.onDestroy();
    Toast.makeText(this, "Service Stopped", Toast.LENGTH_LONG).show();
}

这是我的xml文件

<CheckBoxPreference
    android:title="Enable/Disable Alarm"
    android:defaultValue="true"
    android:key="cbAlarm"
    android:summary="Enable or disable alarm" />

这是我的日志

05-06 09:13:53.230: D/dalvikvm(5351): GC_EXTERNAL_ALLOC freed 39K, 50% free  2725K/5379K, external 0K/0K, paused 124ms
05-06 09:13:53.355: D/dalvikvm(5351): GC_EXTERNAL_ALLOC freed 21K, 49% free 2779K/5379K, external 504K/518K, paused 18ms
05-06 09:13:53.420: D/CLIPBOARD(5351): Hide Clipboard dialog at Starting input: finished by someone else... !
05-06 09:13:57.975: I/MediaPlayer(5351): uri is:content://media/internal/audio/media/44
05-06 09:13:57.975: I/MediaPlayer(5351): inside  getAudioFilePath: content://media/internal/audio/media/44
05-06 09:13:57.980: I/MediaPlayer(5351): The actual path is:/system/media/audio/ringtones/S_A_cricket_chirps.ogg
05-06 09:13:57.980: I/MediaPlayer(5351): path is: /system/media/audio/ringtones/S_A_cricket_chirps.ogg
05-06 09:13:57.980: I/MediaPlayer(5351): file path found for DRM file:path is: /system/media/audio/ringtones/S_A_cricket_chirps.ogg
05-06 09:13:57.980: E/MediaPlayer-JNI(5351): setDataSource: outside path in JNI is ?x@
05-06 09:14:20.525: E/ActivityThread(5351): Service com.zafar.test.BatteryService has leaked IntentReceiver com.zafar.test.BatteryService$1@40536548 that was originally registered here. Are you missing a call to unregisterReceiver()?
05-06 09:14:20.525: E/ActivityThread(5351): android.app.IntentReceiverLeaked: Service com.zafar.test.BatteryService has leaked IntentReceiver com.zafar.test.BatteryService$1@40536548 that was originally registered here. Are you missing a call to unregisterReceiver()?
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.LoadedApk$ReceiverDispatcher.<init>(LoadedApk.java:756)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.LoadedApk.getReceiverDispatcher(LoadedApk.java:551)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ContextImpl.registerReceiverInternal(ContextImpl.java:866)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ContextImpl.registerReceiver(ContextImpl.java:853)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ContextImpl.registerReceiver(ContextImpl.java:847)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.content.ContextWrapper.registerReceiver(ContextWrapper.java:318)
05-06 09:14:20.525: E/ActivityThread(5351):     at com.zafar.test.BatteryService.onStartCommand(BatteryService.java:35)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2043)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ActivityThread.access$2800(ActivityThread.java:117)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:998)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.os.Looper.loop(Looper.java:130)
05-06 09:14:20.525: E/ActivityThread(5351):     at android.app.ActivityThread.main(ActivityThread.java:3691)
05-06 09:14:20.525: E/ActivityThread(5351):     at java.lang.reflect.Method.invokeNative(Native Method)
05-06 09:14:20.525: E/ActivityThread(5351):     at java.lang.reflect.Method.invoke(Method.java:507)
05-06 09:14:20.525: E/ActivityThread(5351):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
05-06 09:14:20.525: E/ActivityThread(5351):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
05-06 09:14:20.525: E/ActivityThread(5351):     at dalvik.system.NativeStart.main(Native Method)
05-06 09:14:37.810: D/CLIPBOARD(5351): Hide Clipboard dialog at Starting input: finished by someone else... !

请帮忙。我哪里出错了。

编辑

private BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
        int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);

        if(plugged == 2) {

                SharedPreferences getAlarms = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
                String alarms = getAlarms.getString("ringtone", "default ringtone");
                //getting uri from MediaStore via filepath i.e. content://media/internal/audio/media/29
                Uri uri = Uri.parse(alarms);

                mMediaPlayer = new MediaPlayer();
                try {
                    mMediaPlayer.setDataSource(context, uri);
                    final AudioManager audioManager = (AudioManager) context
                            .getSystemService(Context.AUDIO_SERVICE);
                    if (audioManager.getStreamVolume(AudioManager.STREAM_ALARM) != 0) {
                        mMediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
                        mMediaPlayer.prepare();
                        mMediaPlayer.start();
                    }
                } catch (IOException e) {
                    //System.out.println("OOPS");
                    e.getStackTrace();
                }
        } else if(plugged == 0) {
            mMediaPlayer.stop();
        }

    }
};

Answer 1

确保在 onDestroy 完成之前调用 unregisterReceiver。在 onDestroy 之后，Service 的上下文无效，因此所有已注册的 Intent Receiver 将停止运行。 Android 会通过“泄漏的 Intent 接收器”异常警告您您的应用行为不当。

音乐不会停止，因为接收器不再被调用。您应该确保在 onDestroy 返回之前调用 mMediaPlayer.stop。我建议您将所有这些功能提取到单独的方法中，这样编写您的应用程序会容易得多。

private void startMusic(int level);
private void stopMusic();

此外，如果由于错误而连续收到两个 plugged == 2 intent，请注意不要泄漏 mMusicPlayer。以防御方式编写代码总是比依赖调用者的额外知识更好。

异常处理在您的代码中也很危险。如果音乐启动失败，可能会在你想停止音乐时出现空指针异常。

希望这对您有所帮助。