setVolumeControlStream(int streamType)

Android中有如下几种音频流：

AudioManager.STREAM_MUSIC /** The audio stream for music playback */

AudioManager.STREAM_RING /** The audio stream for the phone ring */

AudioManager.STREAM_ALARM /** The audio stream for alarms */

AudioManager.STREAM_NOTIFICATION /** The audio stream for notifications */

AudioManager.STREAM_SYSTEM /** The audio stream for system sounds */

AudioManager.STREAM_VOICECALL /** The audio stream for phone calls */