持有CTRL时的后wm_keydown？

Question

如果我在发送postmessage包含wm_keydown时将ctrl键向下键，则与消息“混乱”。

我不明白，如果它发送ctrl加上正在发送的消息，或者是什么？

如何复制：

启动记事本并按住ctrl键在代码运行时

#include <windows.h>
#include <iostream>

struct extraKeyInfo
{
    unsigned short repeatCount;
    unsigned char scanCode;
    bool extendedKey, prevKeyState, transitionState;

    operator unsigned int()
    {
        return repeatCount | (scanCode << 16) | (extendedKey << 24) |
            (prevKeyState << 30) | (transitionState << 31);
    }
};


int _tmain(int argc, _TCHAR* argv[])
{

    auto hwnd = FindWindow(0, L"Untitled - Notepad");
    HWND hEdit = FindWindowEx(hwnd, NULL, TEXT("Edit"), NULL);

    for (char ch = 'a'; ch <= 'z'; ch++) // Output a-z in Notepad
    {
        short vkCode = LOBYTE(VkKeyScan(ch));

        extraKeyInfo lParam = {};
        lParam.scanCode = MapVirtualKey(vkCode, MAPVK_VK_TO_VSC);

        PostMessage(hEdit, WM_KEYDOWN, vkCode, lParam);

        lParam.repeatCount = 1;
        lParam.prevKeyState = true;
        lParam.transitionState = true;

        PostMessage(hEdit, WM_KEYUP, vkCode, lParam);
        Sleep(200);
    }

}

可以以某种方式将所需的密钥仅发送到postmessage ippertion如果我有任何钥匙吗？