Android Broadcast Receiver

Hey, in this tutorial we will learn to implement Broadcast Receiver in your Android app. Broadcast Receivers are implemented to respond to the messages broadcasted by the system or by other applications.

First create a button which will trigger a broadcast from our application.

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.codingredefined.broadcastreceiver.MainActivity" >

    <Button
        android:id="@+id/btnStartService"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Broadcast Intent"
        android:onClick="broadcastIntent"
        />

</RelativeLayout>

After creating the button make changes in the MainActivity.java file.

package com.codingredefined.broadcastreceiver;

import android.support.v7.app.ActionBarActivity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

public class MainActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    

    //broadcast a custom intent

    public void broadcastIntent(View view)

    {

    Intent intent= new Intent();

    intent.setAction("com.codingredefined.CUSTOM_INTENT");

    sendBroadcast(intent);

    }

}

Following the changes done in the MainActivity file, then we need to create a new file MyReceiver.java which will respond to the broadcast messages.

package com.codingredefined.broadcastreceiver;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver{

@Override

public void onReceive(Context context, Intent intent) {

// TODO Auto-generated method stub

Toast.makeText(context, "Broadcast Received", Toast.LENGTH_LONG).show();

}

}

Now finally we need to register our broadcast receiver in the manifest file.

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.codingredefined.broadcastreceiver"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="21" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <receiver android:name="MyReceiver">

            <intent-filter>

                <action android:name="com.codingredefined.CUSTOM_INTENT"></action>

            </intent-filter>

        </receiver>

    </application>

</manifest>

Now the application is ready to run.

Android Background Service

Hey, in this tutorial I will demonstrate how to enable your application to continue working in the background without requiring any user interaction.

To start with, first of all create 2 buttons to start and stop the background service.

<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"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.codingreedefined.backgroundservice.MainActivity" >

    <Button

        android:id="@+id/btnStartService"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="Start Service"

        android:onClick="startService"

    />

    

    <Button

        android:id="@+id/btnStopService"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_below="@+id/btnStartService"

        android:text="Stop Service"

        android:onClick="stopService"

    />

</RelativeLayout>

After creating the buttons write functions to start and stop the background service in MainActivity file.

package com.codingreedefined.backgroundservice;

import android.support.v7.app.ActionBarActivity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

public class MainActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    

    //Method to start the service

    public void startService(View view)

    {

    startService(new Intent(getBaseContext(), MyService.class));

    }

    

    //Method to start the service

    public void stopService(View view)

    {

    stopService(new Intent(getBaseContext(), MyService.class));

    }

    

}

Now create a new Java class named MyService and extend Service. Finally write the following code.

package com.codingreedefined.backgroundservice;

import android.app.Service;

import android.content.Intent;

import android.os.IBinder;

import android.widget.Toast;

public class MyService extends Service 

{

@Override

public IBinder onBind(Intent intent) {

// TODO Auto-generated method stub

return null;

}

@Override

public int onStartCommand(Intent intent, int flags, int startId)

{

//let it continue running until it is stopped

Toast.makeText(this, "Service Started!!!", Toast.LENGTH_SHORT).show();

return START_STICKY;

}

@Override

public void onDestroy()

{

super.onDestroy();

Toast.makeText(this, "Service Stopped!!!", Toast.LENGTH_SHORT).show();

}

}

Finally add <service /> tag in the manifest file and run the application.

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.codingreedefined.backgroundservice"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="21" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <service android:name=".MyService" />

    </application>

</manifest>

The following output shall be obtained.

Hide Source Code of Web Pages

<!DOCTYPE html>
<html>
<head>
<!-- Code to prevent use of Ctrl+U -->
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(document).on('keydown',function(e)
{
    var key = e.charCode || e.keyCode;
    if(key == 17 || key == 85)
        {
e.preventDefault();
}
});
</script>
</head>
<!-- Use oncontextmenu="return false" to disable right-click -->
<body oncontextmenu="return false">
<h2>Coding Redefined</h2>
</body>
</html>