Android系统音量类型

    /** The audio stream for phone calls */    public static final int STREAM_VOICE_CALL = AudioSystem.STREAM_VOICE_CALL;    /** The audio stream for system sounds */    public static final int STREAM_SYSTEM = AudioSystem.STREAM_SYSTEM;    /** The audio stream for the phone ring */    public static final int STREAM_RING = AudioSystem.STREAM_RING;    /** The audio stream for music playback */    public static final int STREAM_MUSIC = AudioSystem.STREAM_MUSIC;    /** The audio stream for alarms */    public static final int STREAM_ALARM = AudioSystem.STREAM_ALARM;    /** The audio stream for notifications */    public static final int STREAM_NOTIFICATION = AudioSystem.STREAM_NOTIFICATION;    /** @hide The audio stream for phone calls when connected to bluetooth */    public static final int STREAM_BLUETOOTH_SCO = AudioSystem.STREAM_BLUETOOTH_SCO;    /** @hide The audio stream for enforced system sounds in certain countries (e.g camera in Japan) */    public static final int STREAM_SYSTEM_ENFORCED = AudioSystem.STREAM_SYSTEM_ENFORCED;    /** The audio stream for DTMF Tones */    public static final int STREAM_DTMF = AudioSystem.STREAM_DTMF;    /** @hide The audio stream for text to speech (TTS) */    public static final int STREAM_TTS = AudioSystem.STREAM_TTS;