"尝试确定电池电量时,不允许IntentReceiver组件注册接收意图"

Question

我正在尝试按照http://developer.android.com/training/monitoring-device-state/battery-monitoring.html上的指南从我的应用程序获取电池信息

这是检查电池电量的方法:

public void sendBatteryInfoMessage(){

    IntentFilter iFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
    Intent batteryStatus = c.registerReceiver(null, iFilter);

    int status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
    boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING || status == BatteryManager.BATTERY_STATUS_FULL;

    int chargePlug = batteryStatus.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
    boolean isUsbCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_USB;
    boolean isAcCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_AC;

    int batteryLevel = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
    int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

    float batteryPct = batteryLevel / (float) scale;

}

cContext在类的早期初始化为对象.

这是我收到的错误消息

    07-24 18:11:23.445      634-634/wifi.myapp.sudara.lk.sudara_app W/dalvikvm? threadid=1: thread exiting with uncaught exception (group=0x40028890)
07-24 18:11:23.485      634-634/wifi.myapp.sudara.lk.sudara_app E/AndroidRuntime? FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start receiver wifi.myapp.sudara.lk.sudara_app.SmsActivity: android.content.ReceiverCallNotAllowedException: IntentReceiver components are not allowed to register to receive intents
            at android.app.ActivityThread.handleReceiver(ActivityThread.java:2821)
            at android.app.ActivityThread.access$3200(ActivityThread.java:125)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2083)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:123)
            at android.app.ActivityThread.main(ActivityThread.java:4627)
            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: android.content.ReceiverCallNotAllowedException: IntentReceiver components are not allowed to register to receive intents
            at android.app.ReceiverRestrictedContext.registerReceiver(ContextImpl.java:138)
            at android.app.ReceiverRestrictedContext.registerReceiver(ContextImpl.java:132)
            at wifi.myapp.sudara.lk.sudara_app.BatteryInfo.sendBatteryInfoMessage(BatteryInfo.java:25)
            at wifi.myapp.sudara.lk.sudara_app.SmsActivity.onReceive(SmsActivity.java:53)
            at android.app.ActivityThread.handleReceiver(ActivityThread.java:2810)
            at android.app.ActivityThread.access$3200(ActivityThread.java:125)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2083)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:123)
            at android.app.ActivityThread.main(ActivityThread.java:4627)
            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)

我需要知道的是它的意义IntentReceiver components are not allowed to register to receive intents以及如何克服它.

谢谢

Answer 1

代替:

c.registerReceiver(null, iFilter)

使用:

c.getApplicationContext().registerReceiver(null, iFilter)

该Context传递给onReceive()进行呼叫阻塞registerReceiver(),即使有null BroadcastReceiver.