[DllImport("user32.dll", EntryPoint = "GetKeyboardState")]
public static extern int GetKeyboardState(byte[] pbKeyState);
//定义键盘变量及函数
[DllImport("user32")]
static extern void keybd_event(
byte bVk,
byte bScan,
uint dwFlags,
uint dwExtraInfo
);
const uint KEYEVENTF_EXTENDEDKEY = 0x1;
const uint KEYEVENTF_KEYUP = 0x2;
/// <summary>
/// 模拟按键
/// </summary>
/// <param name="key"></param>
public static void KeyBoardDo(int key)
{
    keybd_event((byte)key, 0x45, KEYEVENTF_EXTENDEDKEY | 0, 0);
    keybd_event((byte)key, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
}
/// <summary>
/// 模拟按键
/// </summary>
/// <param name="key"></param>
public static void KeyBoardDo(int[] key)
{
    foreach (int k in key)
    {
        keybd_event((byte)k, 0x45, KEYEVENTF_EXTENDEDKEY | 0, 0);
    }
    foreach (int k in key)
    {
        keybd_event((byte)k, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
    }
}
/// <summary>
/// 获取大小写状态 True为大写  False为小写
/// </summary>
public static bool CapsLockStatus
{
    get
    {
        byte[] bs = new byte[256];
        GetKeyboardState(bs);
        return (bs[0x14] == 1);
    }
}
/// <summary>
/// 设置大小写状态
/// </summary>
/// <param name="result"></param>
public static void SetCapsLock(bool result)
{
    if (CapsLockStatus != result)
    {
        KeyBoardDo(20);
    }
}