c_cpp 基本的windows api

Posted 2021-05-14

#include <windows.h>

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

int WINAPI WinMain(
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    PSTR szCmdLine,
    int iCmdShow
){
    static TCHAR szClassName[] = TEXT("HelloWin");  //窗口类名
    HWND     hwnd;  //窗口句柄
    MSG      msg;  //消息
    WNDCLASS wndclass;  //窗口类

    /**********第①步：注册窗口类**********/
    //为窗口类的各个字段赋值
    wndclass.style = CS_HREDRAW | CS_VREDRAW;  //窗口风格
    wndclass.lpfnWndProc  = WndProc;  //窗口过程
    wndclass.cbClsExtra   = 0;  //暂时不需要理解
    wndclass.cbWndExtra   = 0;  //暂时不需要理解
    wndclass.hInstance    = hInstance;  //当前窗口句柄
    wndclass.hIcon        = LoadIcon (NULL, IDI_APPLICATION);  //窗口图标
    wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW);  //鼠标样式
    wndclass.hbrBackground= (HBRUSH) GetStockObject (WHITE_BRUSH);  //窗口背景画刷
    wndclass.lpszMenuName = NULL ;  //窗口菜单
    wndclass.lpszClassName= szClassName;  //窗口类名

    //注册窗口
    RegisterClass(&wndclass);

    /*****第②步：创建窗口(并让窗口显示出来)*****/
    hwnd = CreateWindow(
        szClassName,  //窗口类的名字
        TEXT("Welcome"),  //窗口标题（出现在标题栏）
        WS_OVERLAPPEDWINDOW,  //窗口风格
        CW_USEDEFAULT,  //初始化时x轴的位置
        CW_USEDEFAULT,  //初始化时y轴的位置
        500,  //窗口宽度
        300,  //窗口高度
        NULL,  //父窗口句柄
        NULL,  //窗口菜单句柄
        hInstance,  //当前窗口的句柄
        NULL  //不使用该值
    );

    //显示窗口
    ShowWindow (hwnd, iCmdShow);
    //更新（绘制）窗口
    UpdateWindow (hwnd);

    /**********第③步：消息循环**********/
    while( GetMessage(&msg, NULL, 0, 0) ){
        TranslateMessage(&msg);  //翻译消息
        DispatchMessage (&msg);  //分派消息
    }

    return msg.wParam;
}

/**********第④步：窗口过程**********/
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){
    HDC         hdc;  //设备环境句柄
    PAINTSTRUCT ps;
    RECT        rect;

    switch (message){
        //窗口绘制消息
        case WM_PAINT:
            hdc = BeginPaint (hwnd, &ps) ;
            GetClientRect (hwnd, &rect) ;
            DrawText(
                hdc,
                TEXT("你好，欢迎来到C语言中文网"),
                -1,
                &rect,
                DT_SINGLELINE | DT_CENTER | DT_VCENTER
            );
            EndPaint (hwnd, &ps) ;
            return 0 ;

        //窗口销毁消息
        case WM_DESTROY:
            PostQuitMessage(0) ;
            return 0 ;
    }
    return DefWindowProc(hwnd, message, wParam, lParam) ;
}