我用getch（）函数读取键盘，但是发现CTRL和shift和win键和Caps Lock和 Num Look等不能识别。请问如何识别这些键呢？

#include <stdio.h>
#include <conio.h>

void main(void)
{
    int ch, scan;

    do {
        ch = getch();    /* 1st getch() gets ASCII code */
        printf("Character is %d\n", ch);
           if (ch == 0x00 || ch == 0XE0)  { /* if extended key */
            scan = getch();  /* 2nd getch() gets "scan code" */
            printf("\tExtended character:  scan is %d\n", scan);
        }
    }  while (ch != 27);    /* exit loop on ESC */
}

windows环境可用 WH_KEYBOARD_LL 消息，或 WH_KEYBOARD_LL HOOK（钩子）。

如果只是检测虚拟键的状态（DOWN、UP等），可用API GetKeyState()、GetAsyncKevState()、GetKeyboardState()和SetKeyboardState()。

这些API都在函数都在哪里？什么地方能知道它的使用方法？

#include <stdio.h>
#include <windows.h>
main()
{
    SHORT key;
    while (!GetAsyncKeyState(VK_ESCAPE))
    {
        if (GetAsyncKeyState(VK_NUMLOCK) != 0)
            printf("Num Lock 按下\n");
        key = GetKeyState(VK_NUMLOCK);
        if (key==1)
            printf("Num Lock 开\n");
        else if (key==0)
            printf("Num Lock 关\n");
        Sleep(1000);
    }
}

用 API ReadConsoleInput() 得到键盘虚拟键码：
#include <stdio.h>
#include <windows.h>
main()
{
    HANDLE hIn;
    INPUT_RECORD InRec;
    DWORD NumRead;
    WORD VKey = 0;
    hIn = GetStdHandle(STD_INPUT_HANDLE);
    while (VKey != VK_ESCAPE)
    {
        if (ReadConsoleInput(hIn, &InRec, 1, &NumRead))
        {
            if (InRec.EventType == KEY_EVENT)
            {
                if (InRec.Event.KeyEvent.bKeyDown == 0)
                {
                    VKey = InRec.Event.KeyEvent.wVirtualKeyCode;
                    printf("%d\n", VKey);
                }
            }
        }
    }
}