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。