C# 二种方法控制系统音量/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

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[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); }

方法二: 改变程序音量，但不改变系统音量设置

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[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 }