Volume Control

In questo esempio andiamo ad utilizzare SeekBar per il controllo del volume con il metodo:
audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC) e
audioManager.getStreamMinVolume(AudioManager.STREAM_MUSIC)  per ottenere l’avanzamento della SeekBar in base all’ indice del volume corrente:

activity_main.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<LinearLayout
xmlns:android=”http://schemas.android.com/apk/res/android&#8221;
android:layout_width=”match_parent”
android:layout_height=”match_parent”
android:gravity=”center”
android:orientation=”vertical”>

<SeekBar
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:id=”@+id/seekBar”/>

</LinearLayout>

MainActivity.java
package com.example.volumeControl.activities;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import com.example.volumeControl.R;
import android.widget.*;
import android.media.*;
import android.content.*;

public class MainActivity extends AppCompatActivity {
SeekBar seekBar;
AudioManager audioManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

seekBar=findViewById(R.id.seekBar);
audioManager=(AudioManager)getSystemService(Context.AUDIO_SERVICE);

seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){

@Override
public void onProgressChanged(SeekBar seekBar,int progress,boolean fromUser){

audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,progress,AudioManager.FLAG_SHOW_UI);

seekBar.setMax(audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC));
seekBar.setMin(audioManager.getStreamMinVolume(AudioManager.STREAM_MUSIC));

}

@Override
public void onStartTrackingTouch(SeekBar seekBar){

}

@Override
public void onStopTrackingTouch(SeekBar seekBar){

}
});
    }

}