MFC例子

#include

#include

#include

using namespace std;

 

//回调函数原型声明,返回长整形的结果码,CALLBACK是表示stdcall调用

LRESULT CALLBACK WinProc(

                                                                 HWND hwnd,      // handle to window

                                                                 UINT uMsg,      // message identifier

                                                                 WPARAM wParam,  // first message parameter

                                                                 LPARAM lParam   // second message parameter

);

 

//(1) WinMain函数,程序入口点函数

int WINAPI WinMain(

                                        HINSTANCE hInstance,      // handle to current instance

                                        HINSTANCE hPrevInstance,  // handle to previous instance

                                        LPSTR lpCmdLine,          // command line

                                        int nCmdShow              // show state

                                        ){

         //(2)

         //一.设计一个窗口类,类似填空题,使用窗口结构体

         WNDCLASS wnd;

         wnd.cbCl***tra = 0; //类的额外内存

         wnd.cbWndExtra = 0;  //窗口的额外内存

         wnd.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);//创建一个空画刷填充背景

         //加载游标,如果是加载标准游标,则第一个实例标识设置为空

         wnd.hCursor = LoadCursor(NULL, IDC_CROSS);

         wnd.hIcon = LoadIcon(NULL, IDI_ERROR);

         wnd.hInstance = hInstance;//实例句柄赋值为程序启动系统分配的句柄值

         wnd.lpfnWndProc = WinProc;//消息响应函数

         wnd.lpszClassName = "gaojun";//窗口类的名子,在注册时会使用到

         wnd.lpszMenuName = NULL;//默认为NULL没有标题栏

         wnd.style = CS_HREDRAW | CS_VREDRAW;//定义为水平和垂直重画

         //二.注册窗口类

         RegisterClass(&wnd);

         //三.根据定制的窗口类创建窗口

         HWND hwnd;//保存创建窗口后的生成窗口句柄用于显示

         //如果是多文档程序,则最后一个参数lParam必须指向一个CLIENTCREATESTRUCT结构体

         hwnd = CreateWindow("gaojun", "WIN32应用程序", WS_OVERLAPPEDWINDOW,

 CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, NULL, NULL, hInstance, NULL);

         //四.显示窗口

         ShowWindow(hwnd, SW_SHOWDEFAULT);

         //五.更新窗口

         UpdateWindow(hwnd);

        

         //(3).消息循环

         MSG msg;//消息结构体

         //如果消息出错,返回值是-1,当GetMessage从消息队列中取到是WM_QUIT消息时,返回值是0

    //也可以使用PeekMessage函数从消息队列中取出消息

         BOOL bSet;

         while((bSet = GetMessage(&msg, NULL, 0, 0)) != 0){

                   if (-1 ==  bSet)

                   {

                            return -1;

                   }

                   else{

                            TranslateMessage(&msg);

                            DispatchMessage(&msg);

                   }

         }

         return 0;//程序结束,返回0

}

 

//消息循环中对不同的消息各类进行不同的响应

//将winc中的前四个参数传递给WinProc函数

LRESULT CALLBACK WinProc(

                                                         HWND hwnd,      // handle to window

                                                         UINT uMsg,      // message identifier

                                                         WPARAM wParam,  // first message parameter

                                                         LPARAM lParam   // second message parameter

                                                         ){

         switch (uMsg)

         {

         case WM_CHAR://字符按键消息

                   char szChar[20];

                   sprintf(szChar, "char is %d;", wParam);//格式化操作,stdio.h

                   MessageBox(hwnd, szChar, "gaojun", 0);//输出操作windows.h中

                   break;

         case WM_LBUTTONDOWN://鼠标左键按下消息

                   MessageBox(hwnd, "this is click event!", "点击", 0);

                   HDC hdc;

                   hdc = GetDC(hwnd);//获取设备上下文句柄,用来输出文字

                   //在x=0,y=50(像素)的地方输出文字

                   TextOut(hdc, 0, 50, "响应WM_LBUTTONDONW消息!",

strlen("响应WM_LBUTTONDONW消息!"));

                   ReleaseDC(hwnd, hdc);//在使用完DC后一定要注意释放

                   break;

         case WM_PAINT://窗口重给时报消息响应

                   HDC hDc;

                   PAINTSTRUCT ps;

                   hDc = BeginPaint(hwnd, &ps);

                   TextOut(hDc, 0, 0, "这是一个Paint事件!", strlen("这是一个Paint事件!"));

                   EndPaint(hwnd, &ps);

                   break;

         case WM_CLOSE://关闭消息

                   if (IDYES == MessageBox(hwnd, "确定要关闭当前窗口?", "提示", MB_YESNO))

                   {

                            DestroyWindow(hwnd);//销毁窗口

                   }                

                   break;

         case WM_DESTROY:

                   PostQuitMessage(0);//在响应消息后,投递一个退出的消息使用程序安全退出

                   break;

         default:

                   return DefWindowProc(hwnd, uMsg, wParam, lParam);//调用缺省的消息处理过程函数

         }

         return 0;