SendInput和64位

Question

下面是我用来通过SendInput应用程序接口模拟按键的一些代码的摘录。如果我将我的应用程序设置为针对x86处理器进行编译，但不适用于x64 CPU编译，则可以正确执行此操作。

我猜这与x64使用双倍大小指针的事实有关，但我试图将此[FieldOffset(4)]更改为此[FieldOffset(8)]，但它不起作用。

这是否与它正在导入32位版本的user32.dll有关？

    #region SendInput API

    [DllImport("user32.dll", EntryPoint = "SendInput", SetLastError = true)]
    static extern uint SendInput(uint nInputs, INPUT[] pInputs, int cbSize);

    [DllImport("user32.dll", EntryPoint = "GetMessageExtraInfo", SetLastError = true)]
    static extern IntPtr GetMessageExtraInfo();

    private enum KeyEvent
    {
        KeyUp = 0x0002,
        KeyDown = 0x0000,
        ExtendedKey = 0x0001
    }

    private struct KEYBDINPUT
    {
        public ushort wVk;
        public ushort wScan;
        public uint dwFlags;
        public long time;
        public uint dwExtraInfo;
    };

    [StructLayout(LayoutKind.Explicit, Size = 28)]
    private struct INPUT
    {
        [FieldOffset(0)]
        public uint type;
        [FieldOffset(4)]
        public KEYBDINPUT ki;
    };

    #endregion

    public void sendKey(KeyCode Key)
    {
        INPUT[] InputList = new INPUT[2];

        INPUT keyInput = new INPUT();
        keyInput.type = 1;

        keyInput.ki.wScan = 0;
        keyInput.ki.time = 0;
        keyInput.ki.dwFlags = (int)KeyEvent.KeyDown;
        keyInput.ki.dwExtraInfo = (uint)GetMessageExtraInfo();
        keyInput.ki.wVk = (ushort)Key;

        InputList[0] = keyInput;

        keyInput.ki.dwFlags = (int)KeyEvent.KeyUp;

        InputList[1] = keyInput;

        SendInput((uint)2, InputList, Marshal.SizeOf(InputList[0]));
    }

Answer 1

除了SLaks发现的错误之外，剩下的问题是INPUT的大小不正确。这意味着SendInput会失败，因为它接收到了INPUT[]类型的参数。您不能使用StructLayout(LayoutKind.Explicit, Size = 28)指定大小，因为您需要同时处理x86和x64的代码。

这一切都源于在INPUT中只包含了KEYBRDINPUT结构这一事实。MOUSEINPUT结构比KEYBRDINPUT大，这是导致问题的原因。

最好的解决方案是正确定义输入结构，包括联合部分。这样做(声明取自pinvoke.net)。

[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;
}

Answer 2

dwExtraInfo是一个指针。

因此，它需要在32位代码中为4字节宽，在64位代码中为8字节。

要在C#中执行此操作，请使用IntPtr (而不是uint，它始终为4字节)

Answer 3

对于64位平台，唯一需要更改的是INPUT第二个参数的FieldOffset(8) (而不是4)。不需要更改或指定rest结构的大小。这就足够了，而且是完整的(注意，我使用的是默认的InputUnion结构，而不是KEYBDINPUT，但没有区别)：

 [StructLayout(LayoutKind.Explicit)]
    public struct INPUT
    {
    [FieldOffset(0)] public uint Type;
    [FieldOffset(8)] public InputUnion U;
    }

    [StructLayout(LayoutKind.Explicit )]
    public struct InputUnion
    {
        [FieldOffset(0)] public MOUSEINPUT mi;
        [FieldOffset(0)] public KEYBDINPUT ki;
        [FieldOffset(0)] public HARDWAREINPUT hi;
    }


    [StructLayout(LayoutKind.Sequential)]
    public struct MOUSEINPUT
    {
        public int dx;
        public int dy;
        public uint mouseData;
        public uint dwFlags;
        public uint time;
        public  IntPtr dwExtraInfo;
    }


    [StructLayout(LayoutKind.Sequential)]
    public struct KEYBDINPUT
{
    public UInt16 Vk;
    public UInt16 Scan;
    public UInt32 Flags;
    public UInt32 Time;
    public IntPtr ExtraInfo;
}

    [StructLayout(LayoutKind.Sequential)]
    public struct HARDWAREINPUT
    {
        public uint uMsg;
        public ushort wParamL;
        public ushort wParamH;
    }