[C语言]（一）第一个Windows 32 API的窗口程序

#include <windows.h>

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

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int ICmdShow) {
    static TCHAR szAppName[] = TEXT("windowOfC");

    HWND hwnd;//窗体句柄变量
    MSG msg;//消息变量
    WNDCLASS wndclass;//窗口类变量

    //配置窗口类结构
    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    //注册窗口类
    if (!RegisterClass(&wndclass)) {
        MessageBox(NULL, TEXT("注册窗口类失败！"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,
        TEXT("C语言调用Windows API创建的窗口"),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL);

    ShowWindow(hwnd, ICmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;
};

//消息处理方法，windows操作系统的回调函数
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;

    switch (message) {
    case WM_CREATE:
        MessageBox(NULL, TEXT("创建窗口了！"), NULL, MB_ICONERROR);
        return 0;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        GetClientRect(hwnd, &rect);
        DrawText(hdc, TEXT("hello C windows "), -1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        EndPaint(hwnd, &ps);
        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }

    return DefWindowProc(hwnd, message, wParam, lParam);
};