Android BroadcastReceiver没有更新Widget

满堂花醉三千客，一剑霜寒十四洲。这篇文章主要讲述Android BroadcastReceiver没有更新Widget相关的知识，希望能为你提供帮助。
所有的拳头我尝试了所有在stackoverflow上找到的方法，而不是它们的工作方式。
我正在开发一个电池监控应用程序，它包含一些显示信息的小部件。我使用一个名为BatteryUpdateReceiver的通用接收器来收听ACTION_BATTERY_CHANGED事件。我使用此接收器更新显示当前电池电量的小部件。但由于某些原因，它不会更新小部件。我尝试了很多方法，但无法弄清楚什么是错的。我的代码如下。
battery update receiver.java

public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(Intent.ACTION_BATTERY_CHANGED)) { Log.i(TAG, "Receiver ACTION_BATTERY_CHANGED fired"); RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget); AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context.getApplicationContext()); ComponentName thisWidget = new ComponentName(context.getApplicationContext(), BatteryWidget.class); int[] allWidgetIds = appWidgetManager.getAppWidgetIds(thisWidget); for (int i=0; i < allWidgetIds.length; i++) { Log.i(TAG, "WID ID: " + allWidgetIds[i]); appWidgetManager.updateAppWidget(allWidgetIds[i], remoteViews); } } }

battery widget.Java

public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { super.onUpdate(context, appWidgetManager, appWidgetIds); Log.i(TAG, "onUpdate: "); int currentLevel = calculateBatteryLevel(context); if (batteryChanged(currentLevel)) { batteryLevel = currentLevel; Log.i(TAG, "onUpdate: Battery level changed"); } updateViews(context); }private boolean batteryChanged(int currentLevelLeft) { return (batteryLevel != currentLevelLeft); }private int calculateBatteryLevel(Context context) { Log.i(TAG, "calculateBatteryLevel: "); Intent batteryIntent = context.getApplicationContext().registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); int level = batteryIntent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0); int scale = batteryIntent.getIntExtra(BatteryManager.EXTRA_SCALE, 100); return level * 100 / scale; }private void updateViews(Context context) { Log.i(TAG, "updateViews: "); RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widget); views.setTextViewText(R.id.batteryText, batteryLevel + "%"); ComponentName componentName = new ComponentName(context, BatteryWidget.class); AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context); appWidgetManager.updateAppWidget(componentName, views); }

androidManifest.xml中

< receiver android:name=".lib.receivers.BatteryUpdateReceiver" android:enabled="true" /> < receiver android:name=".widget.BatteryWidget" android:label="@string/app_name" > < intent-filter> < action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> < /intent-filter> < meta-data android:name="android.appwidget.provider" android:resource="@xml/batterywidgetinfo" /> < /receiver>

设备启动时，我使用服务注册BatteryUpdateReceiver。

IntentFilter filterBattery = new IntentFilter(); filterBattery.addAction(Intent.ACTION_BATTERY_CHANGED); this.mBatteryStatusReceiver = new BatteryUpdateReceiver(); getApplicationContext().registerReceiver(this.mBatteryStatusReceiver, filterBattery); Log.i(TAG, "Receiver ACTION_BATTERY_CHANGED registered by Service");

我可以确认BatteryUpdateReceiver有效，因为它记录了widget id。此外，如果我将接收器放在BatteryWidget内，那么小部件会更新。谁能告诉我在这里我错过了什么？我知道我可以在onReceive()类中覆盖BatteryWidget方法。但是我如何以这种方式存档呢？
谢谢！
答案您应该从接收器发送ACTION_APPWIDGET_UPDATE广播，而不是直接呼叫updateAppWidget()。
【Android BroadcastReceiver没有更新Widget】像这样的东西：

@Override public void onReceive(Context context, Intent intent) { AppWidgetManager widgetManager = AppWidgetManager.getInstance(getApplicationContext()); int[] appWidgetIds = widgetManager.getAppWidgetIds(new ComponentName(context, BatteryWidget.class)); Intent updateIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE, null, getApplicationContext(), BatteryWidget.class); updateIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetIds); sendBroadcast(updateIntent); }