如何使用C#或VB.Net闪烁键盘指示灯

Question

需要使用C#或VB.net使键盘的发光二极管(大写锁定/数字锁定或滚动锁定发光二极管)闪烁。(使用或不使用互操作都可以)

Answer 1

下面是C语言

#include <windows.h>
#define err if (GetLastError() != 0) return GetLastError();

extern "C" __declspec(dllexport) int __stdcall TurnLed(int state)
{
    DWORD tmp = 4;
    DWORD buf = (2*GetKeyState(VK_NUMLOCK) + 4*GetKeyState(VK_CAPITAL) + state)<<16;
    DefineDosDevice(DDD_RAW_TARGET_PATH, "Kbd", "\\Device\\KeyboardClass1"); err
    HANDLE kbd = CreateFile("\\\\.\\Kbd", GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING,  FILE_ATTRIBUTE_NORMAL,  NULL); err
    DeviceIoControl(kbd, CTL_CODE(FILE_DEVICE_KEYBOARD, 0x0002, METHOD_BUFFERED, FILE_ANY_ACCESS), &buf, sizeof(buf), 0, 0, &tmp, 0); err
    DefineDosDevice(DDD_REMOVE_DEFINITION, "Kbd", 0); err
    CloseHandle(kbd); err
    return 0;
}