How to pick up and hung up calls in android?

This example demonstrates how do I pick up and hung up calls in android.

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"?>
<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:layout_centerInParent="true"
      android:text="Pick up and hung up calls"
      android:textSize="24sp"
      android:textStyle="bold|italic"/>

</RelativeLayout>

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

import android.Manifest;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      if (ContextCompat.checkSelfPermission(MainActivity.this,
         Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED){
         if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
            Manifest.permission.READ_PHONE_STATE)){
            ActivityCompat.requestPermissions(MainActivity.this,
            new String[]{Manifest.permission.READ_PHONE_STATE}, 1);
         }else{
            ActivityCompat.requestPermissions(MainActivity.this,
            new String[]{Manifest.permission.READ_PHONE_STATE}, 1);
         }
      }else{
         notify();
      }
   }
   @Override
   public void onRequestPermissionsResult(int requestCode, String[] permissions,
      int[] grantResults){
         switch (requestCode){
            case 1: {
               if (grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                  if (ContextCompat.checkSelfPermission(MainActivity.this,
                     Manifest.permission.READ_PHONE_STATE)==PackageManager.PERMISSION_GRANTED){
                     Toast.makeText(this, "Permission Granted", Toast.LENGTH_SHORT).show();
                  }
               }else{
                  Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
               }
               return;
            }
         }
      }
}

Step 4 – Right click on the project, Select New -> Java class and add the following code in the callManager.java

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class callManager extends BroadcastReceiver {
   @Override
   public void onReceive(Context context, Intent intent) {
      try{
         Toast.makeText(context, "Pick up call", Toast.LENGTH_SHORT).show();
      }catch (Exception e){
         e.printStackTrace();
      }
   }
}

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">

   <uses-permission android:name="android.permission.READ_PHONE_STATE"/>

   <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>

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 –