Android Application Development Cookbook: 93 Recipes for Building Winning Apps

Recipe 1.4 Sending and Receiving Broadcasts

Android Versions

Level 1 and above

Permissions

None

Source Code to Download at Wrox.com

UsingBroadcastReceiver.zip

In Android, a broadcast enables you to send a message to another part of your application (or another application) so that you can inform it of something happening. In this recipe, you learn how to create a broadcast receiver to listen for broadcasts, as well as send broadcasts to other applications.

Solution

There are two ways to create a broadcast receiver: programmatically through code and declaratively via the AndroidManifest.xml file. The following sections address each possible solution.

Programmatically Registering a Broadcast Receiver

Consider the following activity:

package net.learn2develop.usingbroadcastreceiver;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {
    MyBroadcastReceiver myReceiver;
    IntentFilter intentFilter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myReceiver = new MyBroadcastReceiver();
        intentFilter = new IntentFilter("MY_SPECIFIC_ACTION");
    }
    @Override
    public void onResume() {
        super.onResume();
        //---register the receiver---
 registerReceiver(myReceiver, ...