C#控制系统的音量大小两种方法

[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);
}