模拟窗口类的封装

下面是模拟窗口类CWnd的封装，当然只是很简单的模拟，创建窗口，显示窗口和更新窗口，下面是代码

#include<stdio.h> #include<windows.h> class CWnd { public: CWnd(); BOOL CreateEX( DWORD dwExStyle, // extended window style LPCTSTR lpClassName, // registered class name LPCTSTR lpWindowName, // window name DWORD dwStyle, // window style int x, // horizontal position of window int y, // vertical position of window int nWidth, // window width int nHeight, // window height HWND hWndParent, // handle to parent or owner window HMENU hMenu, // menu handle or child identifier HINSTANCE hInstance, // handle to application instance LPVOID lpParam // window-creation data ); BOOL ShowWindow(int ncmdShow); BOOL UpdateWindow(); public: HWND m_hWnd; }; CWnd::CWnd() { m_hWnd=NULL; } BOOL CWnd::CreateEX( DWORD dwExStyle, // extended window style LPCTSTR lpClassName, // registered class name LPCTSTR lpWindowName, // window name DWORD dwStyle, // window style int x, // horizontal position of window int y, // vertical position of window int nWidth, // window width int nHeight, // window height HWND hWndParent, // handle to parent or owner window HMENU hMenu, // menu handle or child identifier HINSTANCE hInstance, // handle to application instance LPVOID lpParam // window-creation data ) { m_hWnd=::CreateWindowEx(dwExStyle,lpClassName,lpWindowName,dwStyle,x,y,nWidth,nHeight,hWndParent,hMenu,hInstance,lpParam); if(m_hWnd!=NULL) return TRUE; else return FALSE; } BOOL CWnd::ShowWindow(int ncmdShow) { return ::ShowWindow(m_hWnd,ncmdShow); } BOOL CWnd::UpdateWindow() { return ::UpdateWindow(m_hWnd); } LRESULT CALLBACK WinSunProc( HWND hwnd, // handle to window UINT uMsg, // message identifier WPARAM wParam, // first message parameter LPARAM lParam // second message parameter ); int WINAPI WinMain( HINSTANCE hInstance, // handle to current instance HINSTANCE hPrevInstance, // handle to previous instance LPSTR lpCmdLine, // command line int nCmdShow // show state ) { WNDCLASS wndclass; wndclass.cbClsExtra=0; wndclass.cbWndExtra=0; wndclass.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH); wndclass.hCursor=LoadCursor(NULL,IDC_CROSS); wndclass.hIcon=LoadIcon(NULL,IDI_ERROR); wndclass.hInstance=hInstance; wndclass.lpfnWndProc=WinSunProc; wndclass.lpszClassName="kay&&dan"; wndclass.lpszMenuName=NULL; wndclass.style=CS_HREDRAW | CS_VREDRAW; RegisterClass(&wndclass); //Create the Windows CWnd wnd; wnd.CreateEX(WS_EX_LEFTSCROLLBAR,"kay&&dan","My first windows program",WS_OVERLAPPEDWINDOW,30,40,400,600,NULL,NULL,hInstance,NULL); //Show and update the Window wnd.ShowWindow(SW_SHOWNORMAL); wnd.UpdateWindow(); //the Message Recycle MSG msg; while(GetMessage(&msg,NULL,0,0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return 0; } // 窗口过程函数 LRESULT CALLBACK WinSunProc( HWND hwnd, // handle to window UINT uMsg, // message identifier WPARAM wParam, // first message parameter LPARAM lParam // second message parameter ) { switch(uMsg) { case WM_CHAR: char szchar[20]; sprintf(szchar,"char code is %d",wParam); MessageBox(hwnd,szchar,"Attention",MB_OK); break; case WM_LBUTTONDOWN: MessageBox(hwnd,"mouse click","message",0); HDC hdc; hdc=GetDC(hwnd); //不能在响应WM_PAINT消息时调用 TextOut(hdc,50,50,"我的第一个Windows 程序",strlen("我的第一个Windows 程序")); ReleaseDC(hwnd,hdc); break; case WM_PAINT: HDC hDc; PAINTSTRUCT ps; hDc=BeginPaint(hwnd,&ps); TextOut(hDc,0,50,"重画中。。。",strlen("重画中。。。")); EndPaint(hwnd,&ps); break; case WM_CLOSE: if(IDYES==MessageBox(hwnd,"是否关闭窗口","消息",MB_YESNO)); { DestroyWindow(hwnd); } break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hwnd,uMsg,wParam,lParam); } return 0; }

还要说的就是，C++窗口类对象与窗口并不是一回事，他们之间唯一的关系就是C++窗口类对象内部定义了一个窗口句柄变量，保存了与这个C++窗口类对象相关的那个窗口的句柄。窗口在销毁时，与之对应的C++窗口类的对象销毁与否，要看其生命期是否结束。但C++窗口类对象销毁时，与之相关的窗口也将销毁。