win32学习05.父子窗口和缓冲区

- 日理万妓 2022-06-15 12:54 250阅读 0赞

**子窗口创建：**  
风格上加入WS\_CHILD|WS\_VISIBLE  
CreateWindow方法的倒数第四个参数传去父窗口句柄。

**窗口缓冲区**  
窗口类设计的时候有两个参数：  
cbClsExtra  
cbWndExtra

*  前者是窗口类的缓冲区，后者是窗口的缓冲区。
 *  窗口类的缓冲区是所以基于该类创建的窗口共享的。相当于一个父亲。
 *  窗口的缓冲区是自己的，相当于自己的老婆。

下面放代码：

#include <Windows.h>
    #include <iostream>
    
    HINSTANCE g_hInstance = 0; //接收应用程序实例句柄
    
    //注册窗口类
    BOOL RegisterWindowClass(
        LPSTR lpClassName,
        WNDPROC wndproc
        )
    {
        //设计窗口类
        WNDCLASS wndcls;
        wndcls.style = CS_HREDRAW | CS_VREDRAW;
        wndcls.lpfnWndProc = wndproc;
        wndcls.cbClsExtra = 200;//字节为单位，一般为4的倍数，long型数据4字节
        wndcls.cbWndExtra = 200;
        wndcls.hInstance = g_hInstance;
        wndcls.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
        wndcls.hCursor = LoadCursor(NULL,IDC_CROSS);
        wndcls.hIcon = LoadIcon(NULL,IDI_ERROR);
        wndcls.lpszClassName = lpClassName;
        wndcls.lpszMenuName = NULL;
        ATOM nAtom = RegisterClass(&wndcls);//注册窗口类
        if (nAtom == 0)
        {
            return FALSE;
        }
        return TRUE;
    }
    
    //窗口过程函数
    LRESULT CALLBACK WinSunProc(
        HWND hwnd,      
        UINT uMsg,      
        WPARAM wParam,  
        LPARAM lParam   
        )
    {
        switch(uMsg)
        {
        case WM_CHAR: //按下字符键
            char szChar[200];
            sprintf(szChar,"char is %d",wParam);
            MessageBox(hwnd,szChar,"HappyTeemo",0);
            break;
        case WM_LBUTTONDOWN://鼠标左键
            MessageBox(hwnd,"mouse clicked","HappyTeemo",0);
            HDC hdc;
            hdc=GetDC(hwnd);
            TextOut(hdc,0,50,"HappyTeemo",strlen("HappyTeemo"));
            ReleaseDC(hwnd,hdc);
            break;
        case WM_PAINT: //重绘
            HDC hDC;
            PAINTSTRUCT ps;
            hDC=BeginPaint(hwnd,&ps);
            TextOut(hDC,0,0,"HappyTeemo",strlen("HappyTeemo"));
            EndPaint(hwnd,&ps);
            break;
        case WM_CLOSE://关闭
            if(IDYES==MessageBox(hwnd,"Close?","HappyTeemo",MB_YESNO))
            {
                DestroyWindow(hwnd);
            }
            break;
        case WM_DESTROY://销毁
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd,uMsg,wParam,lParam);
        }
        return 0;
    }
    
    //创建父窗口
    HWND CreateFather(LPSTR lpClassName,LPSTR lpWndName)
    {
        HWND hwnd;
        hwnd = CreateWindow(lpClassName,lpWndName,WS_OVERLAPPEDWINDOW,0,0,600,400,NULL,NULL,g_hInstance,NULL);
        return hwnd;
    }
    
    //创建子窗口
    HWND CreatChild(LPSTR lpClassName,LPSTR lpWndName,HWND hParent)
    {
        HWND hwnd;
        hwnd = CreateWindow(lpClassName,lpWndName,WS_CHILD|WS_VISIBLE|WS_OVERLAPPEDWINDOW,0,0,100,100,hParent,NULL,g_hInstance,NULL);
        return hwnd;
    }
    
    //设置缓冲区
    void SetExtra(HWND hwnd)
    {
        LPCTSTR str = "hello";
        //SetClassLong(hwnd,0,100);
        SetClassLong(hwnd,250,(LONG)str); //从250开始放
        //窗口类的附加数据缓冲区：是所以基于该类创建的窗口共享的
        SetWindowLong(hwnd,0,100);
        //窗口自己私有的缓冲区
    
    /********************** DWORD SetClassLong( HWND hWnd, // handle to window，窗口句柄 int nIndex, // index of value to change，字节索引号（首地址） LONG dwNewLong // new value，存入的数据 ); LONG SetWindowLong( HWND hWnd, // handle to window int nIndex, // offset of value to set LONG dwNewLong // new value ); ***********************/
    }
    
    //得到缓冲区
    void GetExtra(HWND hwnd)
    {
        LONG nClassExtra = GetClassLong(hwnd,250);//从250开始读
        LONG nWndExtra = GetWindowLong(hwnd,0);
        char Test[256] = {
       0};
        sprintf(Test,"ClS:%s,Hwnd:%d",(char*)nClassExtra,nWndExtra);
        MessageBox(NULL,Test,"Info",MB_OK);
    /********************** DWORD GetClassLong( HWND hWnd, // handle to window，窗口句柄 int nIndex // offset of value to retrieve，字节索引号 );//返回值接受读取的数据 GetWindowLong(( HWND hWnd, // handle to window，窗口句柄 int nIndex // offset of value to retrieve，字节索引号 );//返回值接受读取的数据 ***********************/
    }
    
    //显示
    void DisplayWindow(HWND hwnd)
    {
        ShowWindow(hwnd,SW_SHOW);
        UpdateWindow(hwnd);
    }
    
    //消息循环
    void MyMessage()
    {
        //定义消息结构体，开始消息循环
        MSG msg = {
       0};
        while(GetMessage(&msg,NULL,0,0))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    
    
    int  APIENTRY WinMain( 
        HINSTANCE hInstance,//当前程序的实例句柄，找到本进程的内存
        HINSTANCE hPrevInstance,  //前一个实例句柄，已经废弃，一般为NULL
        LPSTR lpCmdLine, //命令行参数字符串
        int nShowCmd //窗口的显示方式：最大化，最小化，原样。
        )
    {
        g_hInstance = hInstance;
        LPSTR ClassName = "HappyTeemo";
        RegisterWindowClass(ClassName,WinSunProc);
    
        HWND hMwndF = CreateFather(ClassName,"ParentWindow");
        HWND hMwndC1 = CreatChild(ClassName,"ChildWindow1",hMwndF);
        HWND hMwndC2 = CreatChild(ClassName,"ChildWindow2",hMwndF);
    
        MoveWindow(hMwndC2,310,100,200,200,TRUE); //最后一个参数表示是否删除移动前的窗口
    
        SetExtra(hMwndC1);
        GetExtra(hMwndC2);//只能读到窗口类的缓冲区，读不到子窗口1的缓冲区
    
        DisplayWindow(hMwndF);
        MyMessage();
    
        return 0;
    }