C# 二种步骤控制系统音量/麦克风大小

场景:在做播放设备的时候需要控制音量的大小，下面几种方法将满足你的要求

方法一: 改变系统音量设置

        [DllImport("user32.dll")]        static extern void keybd_event(byte bVk, byte bScan, UInt32 dwFlags, UInt32 dwExtraInfo);        [DllImport("user32.dll")]        static extern Byte MapVirtualKey(UInt32 uCode, UInt32 uMapType);	        private const byte VK_VOLUME_MUTE = 0xAD;        private const byte VK_VOLUME_DOWN = 0xAE;        private const byte VK_VOLUME_UP = 0xAF;        private const UInt32 KEYEVENTF_EXTENDEDKEY = 0x0001;        private const UInt32 KEYEVENTF_KEYUP = 0x0002;        /// <summary>        /// 改变系统音量大小，增加        /// </summary>        public void VolumeUp()        {            keybd_event(VK_VOLUME_UP, MapVirtualKey(VK_VOLUME_UP, 0), KEYEVENTF_EXTENDEDKEY, 0);            keybd_event(VK_VOLUME_UP, MapVirtualKey(VK_VOLUME_UP, 0), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);        }        /// <summary>        /// 改变系统音量大小，减小        /// </summary>        public void VolumeDown()        {            keybd_event(VK_VOLUME_DOWN, MapVirtualKey(VK_VOLUME_DOWN, 0), KEYEVENTF_EXTENDEDKEY, 0);            keybd_event(VK_VOLUME_DOWN, MapVirtualKey(VK_VOLUME_DOWN, 0), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);        }        /// <summary>        /// 改变系统音量大小，静音        /// </summary>        public void Mute()        {            keybd_event(VK_VOLUME_MUTE, MapVirtualKey(VK_VOLUME_MUTE, 0), KEYEVENTF_EXTENDEDKEY, 0);            keybd_event(VK_VOLUME_MUTE, MapVirtualKey(VK_VOLUME_MUTE, 0), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);        }

        [DllImport("Winmm.dll")]        private static extern int waveOutSetVolume(int hwo, System.UInt32 pdwVolume);        [DllImport("Winmm.dll")]        private static extern uint waveOutGetVolume(int hwo, out    System.UInt32 pdwVolume);          #region         private int volumeMinScope = 0;        private int volumeMaxScope = 100;        private int volumeSize = 100;        /// <summary>        /// 音量控制，但不改变系统音量设置        /// </summary>        public int VolumeSize        {            get { return volumeSize; }            set { volumeSize = value; }        }        public void SetCurrentVolume()        {            if (volumeSize < 0)            {                volumeSize = 0;            }            if (volumeSize > 100)            {                volumeSize = 100;            }            System.UInt32 Value = (System.UInt32)((double)0xffff * (double)volumeSize / (double)(volumeMaxScope - v                                 olumeMinScope));//先把trackbar的value值映射到0x0000～0xFFFF范围            //限制value的取值范围            if (Value < 0)            {                Value = 0;            }            if (Value > 0xffff)            {                Value = 0xffff;            }            System.UInt32 left = (System.UInt32)Value;//左声道音量            System.UInt32 right = (System.UInt32)Value;//右            waveOutSetVolume(0, left << 16 | right); //"<<"左移，“|”逻辑或运算        }