SendInput不能在Windows 8(64位)中工作，但可以在Windows 7(32位)中工作

我编写了一个程序，将input发送到游戏和桌面应用程序，而不是从键盘输入。结果如下:

Windows 7(32位):在游戏和桌面应用程序中工作完美。

Windows 8(64位):不能在游戏中工作，但可以在notepad.exe中工作。

那么为什么它不能在win8中工作呢?

代码如下:

      [StructLayout(LayoutKind.Sequential)]
    struct MOUSEINPUT
    {
        public int dx;
        public int dy;
        public uint mouseData;
        public uint dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }
    [StructLayout(LayoutKind.Sequential)]
    struct KEYBDINPUT
    {
        public ushort wVk;
        public ushort wScan;
        public uint dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }
    [StructLayout(LayoutKind.Sequential)]
    struct HARDWAREINPUT
    {
        public int uMsg;
        public short wParamL;
        public short wParamH;
    }
    [StructLayout(LayoutKind.Explicit)]
    struct MouseKeybdHardwareInputUnion
    {
        [FieldOffset(0)]
        public MOUSEINPUT mi;
        [FieldOffset(0)]
        public KEYBDINPUT ki;
        [FieldOffset(0)]
        public HARDWAREINPUT hi;
    }
    [StructLayout(LayoutKind.Sequential)]
    struct INPUT
    {
        public uint type;
        public MouseKeybdHardwareInputUnion mkhi;
    }
    enum SendInputFlags
    {
        KEYEVENTF_EXTENDEDKEY = 0x0001,
        KEYEVENTF_KEYUP = 0x0002,
        KEYEVENTF_UNICODE = 0x0004,
        KEYEVENTF_SCANCODE = 0x0008,
    }
    [DllImport("user32.dll")]
    static extern UInt32 SendInput(UInt32 nInputs, [MarshalAs(UnmanagedType.LPArray, SizeConst = 1)] INPUT[] pInputs, Int32 cbSize);
    public static void StrokeKey(ushort codeOfKey)
    {
        INPUT[] InputData = new INPUT[1];
        ushort ScanCode = codeOfKey;
        InputData[0].type = 1;
        InputData[0].mkhi.ki.wScan = (ushort)ScanCode;
        InputData[0].mkhi.ki.dwFlags = (uint)SendInputFlags.KEYEVENTF_SCANCODE;
        if (SendInput(1, InputData, Marshal.SizeOf(InputData[0])) == 0)
        {
            String blad = "SendInput failed with code: " + Marshal.GetLastWin32Error().ToString();
            System.Diagnostics.Debug.WriteLine(blad);
        }
    }

    public static void ReleaseKey(ushort codeOfKey)
    {
        INPUT[] InputData = new INPUT[1];
        ushort ScanCode = codeOfKey;
        InputData[0].type = 1;
        InputData[0].mkhi.ki.wScan = (ushort)ScanCode;
        InputData[0].mkhi.ki.dwFlags = (uint)SendInputFlags.KEYEVENTF_KEYUP | (uint)SendInputFlags.KEYEVENTF_SCANCODE;
        InputData[0].mkhi.ki.time = 0;
        InputData[0].mkhi.ki.dwExtraInfo = IntPtr.Zero;
        SendInput(1, InputData, Marshal.SizeOf(InputData[0]));
    }