"IntentReceiver components are not allowed to register to receive intents" when trying to determine Battery level

Question

I am trying to get Battery info from my Application following the guidelines at http://developer.android.com/training/monitoring-device-state/battery-monitoring.html

This is the method is came up with to check the battery level:

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;  } 

c is initialized as Context object earlier in the class.

This is the error message I am getting

    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) 

What I need to know is the meaning of IntentReceiver components are not allowed to register to receive intents and how to over come it.

Thank you

Answer 1

Instead of:

c.registerReceiver(null, iFilter) 

use:

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

The Context that is passed to onReceive() is blocked from calling registerReceiver(), even with a null BroadcastReceiver.