Keyboard Input Example

Copy

#include <windows.h>


LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    const wchar_t CLASS_NAME[] = L"MyWindowClass";

    WNDCLASSEXW wc = {0};
    MSG msg;

    // Register the window class
    wc.cbSize = sizeof(WNDCLASSEXW);
    wc.lpfnWndProc = WndProc;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = GetSysColorBrush(COLOR_WINDOW);
    wc.lpszClassName = CLASS_NAME;
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassExW(&wc))
        return 0;

    HWND hwnd = CreateWindowExW(
        WS_EX_CLIENTEDGE,
        CLASS_NAME,
        L"Keyboard Input Demo",
        WS_OVERLAPPEDWINDOW | WS_VISIBLE,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        700,
        350,
        NULL,
        NULL,
        hInstance,
        NULL);

    if (!hwnd)
        return 0;

    // Message loop
    while (GetMessage(&msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return static_cast<int>(msg.wParam);
}

LRESULT CALLBACK WndProc(HWND hwnd,
                         UINT msg,
                         WPARAM wParam,
                         LPARAM lParam)
{
    static wchar_t key[64] = L"";
    static wchar_t chr[64] = L"";

    static int keyLen = 0;
    static int chrLen = 0;

    switch (msg)
    {
        case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);

            TextOutW(hdc, 10, 10, key, keyLen);
            TextOutW(hdc, 10, 35, chr, chrLen);

            EndPaint(hwnd, &ps);
            return 0;
        }

        case WM_KEYDOWN:
        {
            keyLen = wsprintfW(
                key,
                L"Virtual-Key Code: 0x%02X (%u)",
                (UINT)wParam,
                (UINT)wParam);

            InvalidateRect(hwnd, NULL, TRUE);
            return 0;
        }

        case WM_CHAR:
        {
            chrLen = wsprintfW(
                chr,
                L"Character: %lc (0x%04X)",
                (wchar_t)wParam,
                (UINT)wParam);

            InvalidateRect(hwnd, NULL, TRUE);
            return 0;
        }

        case WM_CLOSE:
            DestroyWindow(hwnd);
            return 0;

        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;
    }

    return DefWindowProcW(hwnd, msg, wParam, lParam);
}