How to use LocalBroadcastManager?

Question

How to use/locate LocalBroadcastManager as described in google docs and Service broadcast doc?

I tried to google it, but there is no code available to start with?

The documents say that I should use it if I want to do broadcast internally with in my app's process but I don't know where to look for this.

Any help/comment?

Update: I know how to use Broadcasts but don't know how to get LocalBroadcastManager available in my project.

Answer 1

I'll answer this anyway. Just in case someone needs it.

ReceiverActivity.java

An activity that watches for notifications for the event named "custom-event-name".

@Override public void onCreate(Bundle savedInstanceState) {    ...    // Register to receive messages.   // We are registering an observer (mMessageReceiver) to receive Intents   // with actions named "custom-event-name".   LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,       new IntentFilter("custom-event-name")); }  // Our handler for received Intents. This will be called whenever an Intent // with an action named "custom-event-name" is broadcasted. private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {   @Override   public void onReceive(Context context, Intent intent) {     // Get extra data included in the Intent     String message = intent.getStringExtra("message");     Log.d("receiver", "Got message: " + message);   } };  @Override protected void onDestroy() {   // Unregister since the activity is about to be closed.   LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);   super.onDestroy(); } 

SenderActivity.java

The second activity that sends/broadcasts notifications.

@Override public void onCreate(Bundle savedInstanceState) {    ...    // Every time a button is clicked, we want to broadcast a notification.   findViewById(R.id.button_send).setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v) {       sendMessage();     }   }); }  // Send an Intent with an action named "custom-event-name". The Intent sent should  // be received by the ReceiverActivity. private void sendMessage() {   Log.d("sender", "Broadcasting message");   Intent intent = new Intent("custom-event-name");   // You can also include some extra data.   intent.putExtra("message", "This is my message!");   LocalBroadcastManager.getInstance(this).sendBroadcast(intent); } 

With the code above, every time the button R.id.button_send is clicked, an Intent is broadcasted and is received by mMessageReceiver in ReceiverActivity.

The debug output should look like this:

01-16 10:35:42.413: D/sender(356): Broadcasting message 01-16 10:35:42.421: D/receiver(356): Got message: This is my message!  

Answer 2

I'd rather like to answer comprehensively.

1. LocalbroadcastManager included in android 3.0 and above so you have to use support library v4 for early releases. see instructions here

2. Create a broadcast receiver:

   private BroadcastReceiver onNotice= new BroadcastReceiver() {      @Override     public void onReceive(Context context, Intent intent) {         // intent can contain anydata         Log.d("sohail","onReceive called");         tv.setText("Broadcast received !");      } }; 

3. Register your receiver in onResume of activity like:

   protected void onResume() {         super.onResume();          IntentFilter iff= new IntentFilter(MyIntentService.ACTION);         LocalBroadcastManager.getInstance(this).registerReceiver(onNotice, iff);     }  //MyIntentService.ACTION is just a public static string defined in MyIntentService. 

4. unRegister receiver in onPause:

   protected void onPause() {   super.onPause();   LocalBroadcastManager.getInstance(this).unregisterReceiver(onNotice); } 

5. Now whenever a localbroadcast is sent from applications' activity or service, onReceive of onNotice will be called :).

Edit: You can read complete tutorial here LocalBroadcastManager: Intra application message passing