How to use LocalBroadcastManager?


This example demonstrate about How to use LocalBroadcastManager

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   xmlns:app = "http://schemas.android.com/apk/res-auto"
   xmlns:tools = "http://schemas.android.com/tools"
   android:layout_width = "match_parent"
   android:gravity = "center"
   android:layout_height = "match_parent"
   tools:context = ".MainActivity"
   android:orientation = "vertical">
   <TextView
      android:id = "@+id/actionEvent"
      android:textSize = "40sp"
      android:layout_marginTop = "30dp"
      android:layout_width = "wrap_content"
      android:layout_height = "match_parent" />
</LinearLayout>

In the above code, we have taken text view to show broadcast values.

Step 3 − Add the following code to src/MainActivity.java

<?xml version = "1.0" encoding = "utf-8"?>
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
   TextView actionEvent;
   @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver, new IntentFilter("custom-action-local-broadcast"));
      actionEvent = findViewById(R.id.actionEvent);
      actionEvent.setText("Click");
      actionEvent.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            Intent intent = new Intent("custom-action-local-broadcast");
            intent.putExtra("name","Tutorialspoint.com");
            LocalBroadcastManager.getInstance(MainActivity.this).sendBroadcast(intent);
         }
      });
   }
   private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {
         // Get extra data included in the Intent
         String message = intent.getStringExtra("name");
         actionEvent.setText(message);
      }
   };
}

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –

Now click on textview, it will show the result as shown below –

Click here to download the project code

Updated on: 30-Jul-2019

316 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements