2-设计窗口过程函数

设计窗口过程函数

回调函数指：用户每进行一次操作，就调用的函数（即响应）。

LRESULT CALLBACK my_callback(
    __in HWND hwnd,
    __in UINT uMsg,
    __in WPARAM wParam,
    __in LPARAM lParam)
{
    int ret;
    HDC hdc;
    switch (uMsg)
    {
    case WM_CHAR:
        char szchar[20];
        sprintf_s(szchar, "您刚刚按下了：%c", wParam);
        MessageBox(hwnd, szchar, "char", NULL);
        break;
    case WM_LBUTTONDOWN:
        MessageBox(hwnd, "检测鼠标左键按下", "mes", NULL);
        break;
    case WM_PAINT:
        PAINTSTRUCT ps;
        hdc = BeginPaint(hwnd, &ps);
        TextOut(hdc, 0, 0, "the window has repainted", strlen("the window has repainted"));
        EndPaint(hwnd, &ps);
        MessageBox(hwnd, "重绘", "mes", NULL);
        break;
    case WM_CLOSE:
        ret = MessageBox(hwnd, "是否真的结束", "msg", MB_YESNO);
        if (ret == IDYES)
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd, uMsg, wParam, lParam);
        break;
    }

    return 0;
}

整体代码

1在项目——链接器——系统——子系统中，改为窗口

2改为多字节字符集

#include<windows.h>
#include<stdio.h>

LPCSTR classname = "MY_C";
LPCSTR msgname = "first_window";
LRESULT CALLBACK my_callback(
    __in HWND hWindow,
    __in UINT uMsg,
    __in WPARAM wParam,
    __in LPARAM lParam);


int WINAPI wWinMain(
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    PWSTR pCmdLine,
    int nCmdShow)
{
    WNDCLASS wndcls;
    wndcls.cbClsExtra = NULL;
    wndcls.cbWndExtra = NULL;
    wndcls.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndcls.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndcls.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndcls.hInstance = hInstance;
    wndcls.lpszMenuName = NULL;
    wndcls.style = CS_HREDRAW | CS_VREDRAW;
    wndcls.lpfnWndProc = my_callback;
    wndcls.lpszClassName = classname;

    RegisterClass(&wndcls);
    HWND hwnd;	//创建一个句柄
    hwnd = CreateWindow(
        classname,        // name of window class 
        msgname,            // title-bar string 
        WS_OVERLAPPEDWINDOW, // top-level window 
        CW_USEDEFAULT,       // default horizontal position 
        CW_USEDEFAULT,       // default vertical position 
        CW_USEDEFAULT,       // default width 
        CW_USEDEFAULT,       // default height 
        (HWND)NULL,         // no owner window 
        (HMENU)NULL,        // use class menu 
        hInstance,           // handle to application instance 
        (LPVOID)NULL);      // no window-creation data

    ShowWindow(hwnd, SW_SHOW);
    UpdateWindow(hwnd);

    MSG msg;
    while (GetMessage(&msg, NULL, NULL, NULL))		//只有接收到WM_QUIT才会返回0
    {
        TranslateMessage(&msg);		//将消息转化为相应格式，并投递到消息队列中
        DispatchMessage(&msg);		//分派消息
    }
    return msg.wParam;
}

LRESULT CALLBACK my_callback(
    __in HWND hwnd,
    __in UINT uMsg,
    __in WPARAM wParam,
    __in LPARAM lParam)
{
    int ret;
    HDC hdc;
    switch (uMsg)
    {
    case WM_CHAR:
        char szchar[20];
        sprintf_s(szchar, "您刚刚按下了：%c", wParam);
        MessageBox(hwnd, szchar, "char", NULL);
        break;
    case WM_LBUTTONDOWN:
        MessageBox(hwnd, "检测鼠标左键按下", "mes", NULL);
        break;
    case WM_PAINT:
        PAINTSTRUCT ps;
        hdc = BeginPaint(hwnd, &ps);
        TextOut(hdc, 0, 0, "the window has repainted", strlen("the window has repainted"));
        EndPaint(hwnd, &ps);
        MessageBox(hwnd, "重绘", "mes", NULL);
        break;
    case WM_CLOSE:
        ret = MessageBox(hwnd, "是否真的结束", "msg", MB_YESNO);
        if (ret == IDYES)
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd, uMsg, wParam, lParam);
        break;
    }

    return 0;
}

发布于 2022-11-01