我正在尝试制作一个 Android 电池小部件。问题是有时它会更新，但有时不会。
我必须重新启动手机才能让它再次工作——或者从屏幕上删除它并再次在屏幕上创建它。
我的问题可能是什么？
这是我的代码..这是我唯一的课程。
public class BatteryWidgetProvider extends AppWidgetProvider
{
private RemoteViews views;
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds)
{
context.getApplicationContext().registerReceiver(this, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
ComponentName name = new ComponentName(context, BatteryWidgetProvider.class);
appWidgetManager.updateAppWidget(name, this.views);
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
if(action.equals(intent.ACTION_BATTERY_CHANGED))
{
Integer level = intent.getIntExtra("level", -1);
this.views.setTextViewText(R.id.batter_level, level.toString() + "%");
ComponentName name = new ComponentName(context, BatteryWidgetProvider.class);
AppWidgetManager.getInstance(context).updateAppWidget(name, this.views);
}
super.onReceive(context, intent);
}
我的清单文件看起来像这样..
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<receiver android:name=".BatteryWidgetProvider">
<intent-filter >
<action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="@xml/appwidget_info"/>
</receiver>
</application>
这是我的信息文件...
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:minHeight="72dp"
android:minWidth="144dp"
android:updatePeriodMillis="0" >
</appwidget-provider>
错误....
java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.BATTERY_CHANGED flg=0x60000000 (has extras) } in com.batterywidget.BatteryWidgetProvider@4a38e3f0
at android.app.ActivityThread$PackageInfo$ReceiverDispatcher$Args.run(ActivityThread.java:906)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4633)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.batterywidget.BatteryWidgetProvider.onReceive(BatteryWidgetProvider.java:72)
at android.app.ActivityThread$PackageInfo$ReceiverDispatcher$Args.run(ActivityThread.java:893)