how to increase and decrease the volume programmatically in android

Question

I created the music player app and i want to set the volume up/down programmatically .

I want to implement two another

Answer 1

This code will set the volume 100 instantly with no feedback to the user when buttonSES is pressed.

public void perform_actionSES(View v) {
Button buttonSES = (Button) findViewById(R.id.buttonSES);

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, 100, 0);  
}