Broadcast receiver Activity

Wed, 02/22/2012 - 03:44 | by jozsi

SDK Version:

If you want to catch a broadcasted intent on an Activity, you may get the following error:

02-22 08:18:46.874: E/AndroidRuntime(276): java.lang.RuntimeException: Unable to instantiate receiver com.helloandroid.broadcasttest.BroadcastTestActivity$MyBroadcastReceiver: 
...
java.lang.InstantiationException: com.helloandroid.broadcasttest.BroadcastTestActivity$MyBroadcastReceiver
 
 
...
 
02-22 08:18:46.874: E/AndroidRuntime(276): Caused by: java.lang.InstantiationException: com.helloandroid.broadcasttest.BroadcastTestActivity$MyBroadcastReceiver

This is because you can't instantiate a receiver in an inner class.

Instead of inner receiver, you can manually instantiate a broadcast receiver yourself in the activity.

        private BroadcastReceiver       myBroadCastReceiver     = new BroadcastReceiver()
                {
 
                                @Override
                                public void onReceive( Context context, Intent intent )
                                {
                                                Log.d( "Broadcastreceiver: " + intent.getAction() + " package: "+ intent.getPackage() + " @" + System.currentTimeMillis() );
                                }
                };

No need to set this receiver in the manifest xml file, register it in the activity's onresume method and unregister in the onpause:

    public void onResume() {
        super.onResume();
        ....
        registerReceiver(myBroadcastReceiver, new IntentFilter("your.custom.BROADCAST&quot;));
    }
 
    public void onPause() {
        super.onPause();
        ...
        unregisterReceiver(myBroadcastReceiver);
    }
    ...
}

Thats all, the receiver will catch the broadcasts, if the activity is on the screen.

To broadcast custom intents, use the following method:

                Intent broadCastIntent = new Intent();
 
                broadCastIntent.setAction( "your.custom.BROADCAST&quot; );
                broadCastIntent.setPackage( "com.helloandroid.broadcasttest" );
                
                ApplicationObject.applicationContext.sendBroadcast( broadCastIntent );
 
                Log.d( "Broadcast sent" );

The setPackage() method set an explicit application package name that limits the components the Intent will resolve to.

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