Broadcast Receivers and Intents

Broadcast receivers and intents are fundamental components in Android that enable communication between different parts of your application or even between different applications. Understanding how to use broadcast receivers and intents effectively is crucial for building responsive and interconnected Android applications. In this tutorial, we will explore broadcast receivers and intents in Android.

Introduction to Broadcast Receivers and Intents

A broadcast receiver is a component that allows your application to receive and respond to system-wide or application-specific broadcast messages. These messages are delivered through intents, which are objects that carry information and represent a specific action to be performed. Broadcast receivers enable your application to listen for and react to various events, such as device booting, network connectivity changes, or custom actions triggered within your app.

Creating a Broadcast Receiver

Here's an example of how to create a simple broadcast receiver:

Create a new Android project in your preferred development environment.
Create a new Java class called MyReceiver that extends the BroadcastReceiver class and override the onReceive() method:


    public class MyReceiver extends BroadcastReceiver {
      @Override
      public void onReceive(Context context, Intent intent) {
        // Perform actions based on the received intent
      }
    }

In your AndroidManifest.xml file, declare the receiver by adding the following code inside the <application> tag:


    <receiver android:name=".MyReceiver">
      <intent-filter>
        <action android:name="android.intent.action.MY_ACTION" />
      </intent-filter>
    </receiver>

In this example, the receiver is registered to listen for the "android.intent.action.MY_ACTION" action. You can replace it with any valid action or use system-defined actions.

Sending Broadcast Intents

To send a broadcast intent, you can use the sendBroadcast() method or the LocalBroadcastManager class. Here's an example:


    Intent intent = new Intent("android.intent.action.MY_ACTION");
    intent.putExtra("key", "value");
    sendBroadcast(intent);

Common Mistakes with Broadcast Receivers and Intents

Registering a receiver dynamically but forgetting to unregister it, which can lead to memory leaks.
Using implicit intents without specifying the appropriate action or data to match the receiver.
Performing long-running operations in the receiver's onReceive() method, which can block the main thread and cause ANR errors.