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- How to control volume in android? 1 answer
 
I am writing an app for android that turns up the volume and plays a song for 45 seconds and then stops. That works great, however I can only get the volume to turn up to 50%, Is there a way to turn the volume up to 100% using setVolume()?
This is my code:
final MediaPlayer mp = MediaPlayer.create(context, R.raw.sound_file_1);
//plays eye of the tiger for 45 seconds
if (messages.contains("MUSIC ONLY")){
    //turn up the volume
    mp.setVolume(20, 20);
    mp.start();
    //play ring tone for 45 seconds
    new Timer().schedule(new TimerTask() {
        @Override
        public void run() {
            mp.stop();
        }
    }, 45000);
}
    You can use the following snippet, using AudioManager:
AudioManager am = 
    (AudioManager) getSystemService(Context.AUDIO_SERVICE);
am.setStreamVolume(
    AudioManager.STREAM_MUSIC,
    am.getStreamMaxVolume(AudioManager.STREAM_MUSIC),
    0);
This sets the volume to the maximum level (getStreamMaxVolume()) for the STREAM_MUSIC (which is on example a song played). For other types of sounds, use different value, like STREAM_RING etc.
来源:https://stackoverflow.com/questions/15670524/how-to-turn-the-volume-to-max-programmatically-on-android