Question

I am trying to play some tone when my application is in background and I press on “Camera” button for that I am doing this simple steps.

1. Creating BroadcastReceiver class

   public class CameraButtonListener extends BroadcastReceiver {
       @Override
       public void onReceive(Context context, Intent intent) {
           ToneGenerator tone = new ToneGenerator(AudioManager.STREAM_DTMF, 100);
           tone.startTone(0,2000);
           abortBroadcast();
       }
   }
   

2. Register BrodcastReceiver in onCreate methode.

   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
   
       MediaButtonBrodcastReceiver receiver = new MediaButtonBrodcastReceiver();        
       IntentFilter filter = new IntentFilter(Intent.ACTION_CAMERA_BUTTON);
       filter.setPriority(25645895);
       registerReceiver(receiver,filter);      
   }
   

3. Adding brodcast receiver to android manifest.

   <receiver android:enabled="true" android:exported="true" android:name=".CameraButtonListener">
   <intent-filter android:priority="25645895">
       <action android:name="android.intent.action.CAMERA_BUTTON" />
       <category android:name="android.intent.category.DEFAULT" />
   </intent-filter>
   

After I launch my application, then press menu button and application goes to the background, after I press on Camera Button and nothing heppens, only camera application is opened. Maybe I am doing something wrong or I have missed something ?

I use Sony Ericsson XPeria Arc phone with Android 2.3.4 OS version.

Answer 1

Get rid of the <category> element in your <receiver> element, if you are using step #3. That broadcast probably does not have a category — you usually only see categories on Intent objects used for startActivity().

Note that your step #2 does not specify a category with its IntentFilter, which is fine.