WALLPAPER_CHANGED 的 BroadcastReceiver 多次调用 onReceive()：Android

Question

我有一个 BroadcastReceiver 并这样声明它：

<receiver
    android:name="com.services.Receiver"
    android:enabled="true"
    android:exported="true" >
    <intent-filter android:priority="999" >
        <action android:name="android.intent.action.WALLPAPER_CHANGED" />
    </intent-filter>
</receiver>

接收者是：

@Override
public void onReceive(final Context context, final Intent intent)
{
    change_wallpepar.myPrefs = context.getSharedPreferences("myPrefs", Context.MODE_PRIVATE);
    new Handler().postDelayed(new Runnable()
    {
        @Override
        public void run()
        {
            Log.d("MAYUR", "<< wallpepar changed >>");
            if (change_wallpepar.myPrefs.getLong("temp_for_change", 1) == 0)
            {
                context.stopService(new Intent(context, change_wallpepar.class));
            }
            else
            {
                SharedPreferences.Editor e = change_wallpepar.myPrefs.edit();
                e.putLong("temp_for_change", 0);
                e.commit();
            }
        }
    }, 4000);
}

当我在这里更改壁纸时，它应该被调用一次。它确实按照我的预期工作了一段时间，几分钟后它调用 onreceive() 多次（10-18）次，即使墙纸的更改只完成一次。更奇怪的是，它在三星 Galaxy 平板电脑版本 4.4.2 上运行良好，但在摩托罗拉 (Moto E 4.4.4) 上运行不正常。

我的服务：

public class change_wallpepar extends Service {

    @Override
    public void onCreate()
    {
        // TODO Auto-generated method stub
        super.onCreate();
        mytimer = new Timer();
        wpm = WallpaperManager.getInstance(change_wallpepar.this);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        // TODO Auto-generated method stub
        myPrefs = getSharedPreferences("myPrefs", MODE_PRIVATE);
        intervall = myPrefs.getLong("someValue", 60000);

        path_of_wallpepar.clear();
        path_of_wallpepar.add("" + "/storage/emulated/0/Android/data/WallpeparAppHistoryPhotos/514.jpg");
        path_of_wallpepar.add("" + "/storage/emulated/0/Android/data/WallpeparAppHistoryPhotos/513.jpg");

        DisplayImageOptions defaultOption = new DisplayImageOptions.Builder().cacheInMemory(true).cacheOnDisk(true).bitmapConfig(Bitmap.Config.RGB_565).build();
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(change_wallpepar.this).defaultDisplayImageOptions(defaultOption).build();
        ImageLoader.getInstance().init(config);

        mytimer.schedule(new TimerTask()
        {
            @Override
            public void run()
            {

                try
                {
                    wpm.setBitmap(ImageLoader.getInstance().loadImageSync("file://" + path_of_wallpepar.get(temper)));

                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }

                temper++;

                if (temper == path_of_wallpepar.size())
                    temper = 0;

                SharedPreferences.Editor e = change_wallpepar.myPrefs.edit();
                e.putLong("temp_for_change", 1);
                e.commit();

                Log.e("MAYUR", "wallpepar seted");

            }
        }, 0, intervall);

        return super.onStartCommand(intent, flags, startId);

    }

    @Override
    public IBinder onBind(Intent intent)
    {
        // TODO Auto-generated method stub

        return null;
    }

    public void onDestroy()
    {
        Toast.makeText(this, "Service Destroyed", Toast.LENGTH_SHORT).show();
        Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
        v.vibrate(1000);
        mytimer.cancel();
        super.onDestroy();
    }

}

我的 Logcat 输出是：

## Logcat ##
04-16 11:06:30.654: E/MAYUR(3405): wallpepar seted
04-16 11:06:34.636: D/MAYUR(3405): << wallpepar changed >>
04-16 11:06:59.584: E/MAYUR(3405): wallpepar seted
04-16 11:07:03.551: D/MAYUR(3405): << wallpepar changed >>
04-16 11:07:30.078: E/MAYUR(3405): wallpepar seted
04-16 11:07:33.979: D/MAYUR(3405): << wallpepar changed >>
04-16 11:07:59.433: E/MAYUR(3405): wallpepar seted
04-16 11:08:03.340: D/MAYUR(3405): << wallpepar changed >>
04-16 11:08:30.029: E/MAYUR(3405): wallpepar seted
04-16 11:08:33.933: D/MAYUR(3405): << wallpepar changed >>
04-16 11:08:59.481: E/MAYUR(3405): wallpepar seted
04-16 11:09:03.383: D/MAYUR(3405): << wallpepar changed >>
04-16 11:09:30.066: E/MAYUR(3405): wallpepar seted
04-16 11:09:33.966: D/MAYUR(3405): << wallpepar changed >>
04-16 11:09:59.448: E/MAYUR(3405): wallpepar seted
04-16 11:10:03.353: D/MAYUR(3405): << wallpepar changed >>
04-16 11:10:30.049: E/MAYUR(3405): wallpepar seted
04-16 11:10:33.955: D/MAYUR(3405): << wallpepar changed >>
04-16 11:10:59.455: E/MAYUR(3405): wallpepar seted
04-16 11:11:03.350: D/MAYUR(3405): << wallpepar changed >>
04-16 11:11:30.182: E/MAYUR(3405): wallpepar seted
04-16 11:11:34.177: D/MAYUR(3405): << wallpepar changed >>
04-16 11:11:59.406: E/MAYUR(3405): wallpepar seted
04-16 11:12:03.315: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:30.025: E/MAYUR(3405): wallpepar seted
04-16 11:12:33.929: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:34.103: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:34.298: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:34.497: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:34.676: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:34.854: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.022: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.190: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.355: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.522: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.683: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:35.852: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:36.023: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:36.187: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:36.350: D/MAYUR(3405): << wallpepar changed >>
04-16 11:12:36.513: D/MAYUR(3405): << wallpepar changed >>

Answer 1

很可能是设备特定问题。

一般来说，使用标志我猜是 recommended 解决方案

@Override
public void onReceive(final Context context, final Intent intent)
{
     private static boolean firstReceive = true;
    change_wallpepar.myPrefs = context.getSharedPreferences("myPrefs", Context.MODE_PRIVATE);
    new Handler().postDelayed(new Runnable()
    {
        @Override
        public void run()
        {
           if(firstReceive){
            Log.d("MAYUR", "<< wallpepar changed >>");
            if (change_wallpepar.myPrefs.getLong("temp_for_change", 1) == 0)
            {
                context.stopService(new Intent(context, change_wallpepar.class));
            }
            else
            {
                SharedPreferences.Editor e = change_wallpepar.myPrefs.edit();
                e.putLong("temp_for_change", 0);
                e.commit();
            }
        }
   ///CHANGE firstReceive BASED ON EITHER TIME SINCE LAST WALLPAPER CHANGE
   ///OR ANY OTHER PARAMETER THAT SUITS YOUR REQUIREMENT
    }, 4000);
  }
}

请注意，我没有在循环中再次重置标志，你应该在自上次更改后经过一定时间后[=] 25=] 或 在共享首选项中保存一些当前壁纸标识符并与之匹配并根据您的要求设置标志 等

我们的想法是解决这个问题，这样您就可以克服误报并实际更改为真正的 wallpaper_change 调用。这是 Workaround 而不是问题存在原因的实际解决方案。

Answer 2

我不确定为什么在某些设备上会发生这种情况，但在我看来很可能是该特定设备的问题。虽然我无法解决该问题，但您可能持有一个变量，一旦您的侦听器被击中并在一段时间后重置，该变量就会被切换。因此，这将导致您的听众在短时间内忽略未来的呼叫。将其视为防洪。

我知道这并不能解决您的实际问题，但我希望它能提供合适的解决方法。

Answer 3

重复的 WALLPAPER_CHANGED 调用是由较小的 Android 设备引起的运行图像上的裁剪比例循环以适合屏幕。这是在 AOSP code 中观察到的。当屏幕比例适合或大于图像时，您不太可能看到此行为，因此平板电脑不会出现此行为。

您可以通过仔细检查不良行为的迹象来解决此问题：

long lastExec = System.currentTimeMillis();

@Override
public void onReceive(final Context context, final Intent intent)
{
    change_wallpepar.myPrefs = context.getSharedPreferences("myPrefs", Context.MODE_PRIVATE);
    new Handler().postDelayed(new Runnable()
    {
        @Override
        public void run()
        {
          if(System.currentTimeMillis()-lastExec>1000)
          {
            Log.d("MAYUR", "<< wallpepar changed >>");
            if (change_wallpepar.myPrefs.getLong("temp_for_change", 1) == 0)
            {
                context.stopService(new Intent(context, change_wallpepar.class));
            }
            else
            {
                SharedPreferences.Editor e = change_wallpepar.myPrefs.edit();
                e.putLong("temp_for_change", 0);
                e.commit();
            }
          }
          lastExec = System.currentTimeMillis();
        }
    }, 4000);
}

WALLPAPER_CHANGED 的 BroadcastReceiver 多次调用 onReceive()：Android

BroadcastReceiver for WALLPAPER_CHANGED calls onReceive() multiple times : Android

android

android-service

android-broadcast

android-wallpaper