泄露的意图和报警管理器

Question

我正在尝试创建身份验证系统，如果设备关闭 (SCREEN_OFF) 时间超过 INTERVAL，该系统会弹出登录窗口。

我已经注册了一个 BroadcastReceiver 来监听可启动活动的 onCreate() 中的 SCREEN_ON/OFF 事件：

/* Listen to Screen On & Off events */
  IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
  filter.addAction(Intent.ACTION_SCREEN_OFF);
  BroadcastReceiver screenOnOff = new ScreenOnOff();
  registerReceiver(screenOnOff, filter);

ScreenOnOff -- 是一个 BroadcastReceiver，其功能包括：

@Override
 public void onReceive(Context context, Intent intent) {


mAuthenticationIntent = PendingIntent.getActivity(context, 0,
    new Intent(context, AuthenticationActivity.class), 0);

String action = intent.getAction();

if (action.equals(Intent.ACTION_SCREEN_OFF)) {
   AlarmManager mAlarmManager = (AlarmManager) context
     .getSystemService(context.ALARM_SERVICE);
   mAlarmManager.set(AlarmManager.ELAPSED_REALTIME, System
     .currentTimeMillis()
     + interval, mAuthenticationIntent);

   Log.d(LOG_TAG, "Alarm Set!");
  }

当警报响起时，程序崩溃：

08-27 19:18:02.207: ERROR/ActivityThread(3165): Activity com.artoo.ArtooSlateActivity has leaked IntentReceiver com.artoo.authentication.ScreenOnOff@4495bca0 that was originally registered here. Are you missing a call to unregisterReceiver()?
08-27 19:18:02.207: ERROR/ActivityThread(3165): android.app.IntentReceiverLeaked: Activity com.artoo.ArtooSlateActivity has leaked IntentReceiver com.artoo.authentication.ScreenOnOff@4495bca0 that was originally registered here. Are you missing a call to unregisterReceiver()?
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread$PackageInfo$ReceiverDispatcher.<init>(ActivityThread.java:939)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread$PackageInfo.getReceiverDispatcher(ActivityThread.java:734)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ContextImpl.registerReceiverInternal(ContextImpl.java:791)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ContextImpl.registerReceiver(ContextImpl.java:778)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ContextImpl.registerReceiver(ContextImpl.java:772)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.content.ContextWrapper.registerReceiver(ContextWrapper.java:318)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at com.artoo.ArtooSlateActivity.onCreate(ArtooSlateActivity.java:50)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3815)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread.access$2400(ActivityThread.java:125)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2037)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.os.Looper.loop(Looper.java:123)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at android.app.ActivityThread.main(ActivityThread.java:4627)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at java.lang.reflect.Method.invokeNative(Native Method)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at java.lang.reflect.Method.invoke(Method.java:521)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-27 19:18:02.207: ERROR/ActivityThread(3165):     at dalvik.system.NativeStart.main(Native Method)

任何帮助将不胜感激。

谢谢，萨米尔

Answer 1

由于您动态注册接收器，系统知道您正在泄漏内存，因为您从未对其调用 unregister 。显然你不想取消注册，因为你需要监听 SCREEN_ON/OFF 事件。

解决方案是在 Manifest.xml 中注册接收器

用于接收由 sendBroadcast() 发送的意图的代码的基类。您可以使用 Context.registerReceiver() 动态注册此类的实例，也可以通过 AndroidManifest.xml 中的标记静态发布实现。注意：如果在 Activity.onResume() 实现中注册接收器，则应在 Activity.onPause() 中取消注册它。 （暂停时您不会收到意图，这将减少不必要的系统开销）。不要在 Activity.onSaveInstanceState() 中取消注册，因为如果用户在历史堆栈中移回，则不会调用此方法