android控制系统音量

body_sb=(SeekBar)root.findViewById(R.id.body_sb);
audioManager=(AudioManager)getActivity().getSystemService(Service.AUDIO_SERVICE);
maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);  //获取系统最大音量
body_sb.setMax(maxVolume);   //拖动条最高值与系统最大声匹配
currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);  //获取当前值
body_sb.setProgress(currentVolume);
body_sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, progress, 0);
        currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);  //获取当前值
        body_sb.setProgress(currentVolume);
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
    }
});