Programmatically register a broadcast receiver

Question

What is the best procedure or method for registering a broadcast receiver programmatically? I want to register particular receivers based on user preference.

Since registration is handled by the manifest file, I'm unsure of the best approach to accomplish this in code.

Answer 1

This example shows how to programmatically register a BroadcastReceiver in Android.

Step 1 − Create a new project in Android Studio by selecting File > New Project and entering all the necessary information.

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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Hello World"
      android:layout_centerInParent="true"/>
</RelativeLayout>

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

import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
   ExampleBroadcastReceiver exampleBroadcastReceiver = new ExampleBroadcastReceiver();
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
   }
   protected void onStart(){
      super.onStart();
      IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
      registerReceiver(exampleBroadcastReceiver, filter);
   }
   @Override
   protected void onStop(){
      super.onStop();
      unregisterReceiver(exampleBroadcastReceiver);
   }
}

Step 4 – Add the following code to exampleBroadcastReceiver.java and create a new Java class.

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.widget.Toast;
class ExampleBroadcastReceiver extends BroadcastReceiver {
   @Override
   public void onReceive(Context context, Intent intent) {
      if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {
         boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
         if (noConnectivity) {
            Toast.makeText(context, "Disconnected", Toast.LENGTH_SHORT).show();
         } else {
            Toast.makeText(context, "Connected", Toast.LENGTH_SHORT).show();
         }
      }
   }
}

Step 5 - Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>