android - Set ringer volume programmatically

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:id="@+id/root_layout"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:padding="16dp"     android:orientation="vertical"     android:background="#f44061"     >     <TextView         android:id="@+id/tv_stats"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:textSize="22sp"         android:padding="10dp"         />     <Button         android:id="@+id/btn_ringer_volume"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Set Ringer Volume"         /> </LinearLayout> 

MainActivity.java

 package com.cfsuman.me.androidcodesnippets;  import android.app.Activity; import android.app.NotificationManager; import android.content.Context; import android.content.Intent; import android.media.AudioManager; import android.os.Build; import android.provider.Settings; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView; import android.widget.Toast;  import java.util.Random;   public class MainActivity extends AppCompatActivity {     private Context mContext;     private Activity mActivity;      private LinearLayout mRootLayout;     private Button mBtnRingerVolume;     private TextView mTVStats;      Random mRandom = new Random();      private NotificationManager mNotificationManager;     private AudioManager mAudioManager;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          // Get the application context         mContext = getApplicationContext();         mActivity = MainActivity.this;          // Get the widget reference from xml layout         mRootLayout = findViewById(R.id.root_layout);         mTVStats = findViewById(R.id.tv_stats);         mBtnRingerVolume = findViewById(R.id.btn_ringer_volume);          // Get the notification manager instance         mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);          // Get the audio manager instance         mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);          mBtnRingerVolume.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 // If do not disturb mode on, then off it first                 turnOffDoNotDisturbMode();                  // Get the ringer current volume level                 int current_volume_level = mAudioManager.getStreamVolume(AudioManager.STREAM_RING);                  // Get the ringer maximum volume                 int max_volume_level = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_RING);                  // Get a random volume level in specified range                 int random_volume = mRandom.nextInt(((max_volume_level-0)+1)+0);                  // Set the ringer volume                 mAudioManager.setStreamVolume(                         AudioManager.STREAM_RING,                         random_volume,                         AudioManager.FLAG_SHOW_UI                 );                  // Display the updated status on text view                 mTVStats.setText("Ringer Current Volume : " + current_volume_level);                 mTVStats.append("\nRinger Max Volume : " + max_volume_level);                 mTVStats.append("\nRinger new volume : " + random_volume);             }         });     }      // Custom method to turn off do not disturb mode programmatically     protected void turnOffDoNotDisturbMode(){         if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){ // If api level minimum 23             // If notification policy access granted for this package             if(mNotificationManager.isNotificationPolicyAccessGranted()){{                 if(mAudioManager.getStreamVolume(AudioManager.STREAM_RING)== 0){                     // If do not disturb mode on, then off it                     // Set the interruption filter to all, allow all notification                     mNotificationManager.setInterruptionFilter(mNotificationManager.INTERRUPTION_FILTER_NONE);                     // Show a toast                     Toast.makeText(mContext,"Turn OFF Do Not Disturb Mode",Toast.LENGTH_SHORT).show();                 }             }             }else {                 // Show a toast                 Toast.makeText(mContext,"Going to get grant access",Toast.LENGTH_SHORT).show();                  // If notification policy access not granted for this package                 Intent intent = new Intent(Settings.ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS);                 startActivity(intent);             }         }     } }