audioManager = (AudioManager)getSystemService(Context.AUdio_SERVICE);
    int maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
    int curVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
    SeekBar volControl = (SeekBar)findViewById(R.id.volbar);
    volControl.setMax(maxVolume);
    volControl.setProgress(curVolume);
    volControl.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onStopTrackingTouch(SeekBar arg0) {
        }

        @Override
        public void onStartTrackingTouch(SeekBar arg0) {
        }

        @Override
        public void onProgressChanged(SeekBar arg0,int arg1,boolean arg2) {
            audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,arg1,0);
        }
    });