通过类实例改变类成员变量的值.txt

图像处理学习的一些心得

首先在对话框的构造函数中初始化其成员变量test的值为0；
视图类中：void CMyView::OnMyTest() 
{
	// TODO: Add your command handler code here
	MYTESTDLG AA;
	AA.test=11;
	AA.DoModal();
}
点击弹出对话框中的TEST按键，响应函数为
void MYTESTDLG::OnTest() 
{
	// TODO: Add your control notification handler code here
	int bb=test;
}
这时对话框类的成员变量test值已经被改变为11

另有一例是在视图类中初始化非模态对话框中的一些设定值，而后进行对话框显示，
于是调用对话框类的显示函数OnPaint(),这样就能进行图像显示。
如下：

void CWAVELETView::OnBmpShow() 
{
	CWAVELETDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
//	CString fName= pDoc->GetFilePathTwo();
	CString fName= pDoc->firstname;
	IMAGE_SHOWDLG *myimage= new IMAGE_SHOWDLG();
   //Check if new succeeded and we got a valid pointer to a dialog object
   if(myimage != NULL)
   {
      BOOL ret = myimage->Create(IDD_IMAGE,NULL);
      if(!ret)   //Create failed.
         AfxMessageBox("Error creating Dialog");
	};
......
	myimage->name=fName;
	myimage->m_palDIB=pDoc->GetDocPalette();
	myimage->MoveWindow(0, 0, myRect.Width(), myRect.Height());
   	myimage->ShowWindow(SW_SHOW);
	

}
于是调用对话框类中OnPaint();
void IMAGE_SHOWDLG::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	CFile cf;
	CFileException ex;
	if (!cf.Open(name, 
		CFile::modeRead|CFile::modeReadWrite|CFile::shareDenyRead,&ex))
	{
        TCHAR szError[1024];
        ex.GetErrorMessage(szError, 1024);
		AfxMessageBox(szError);
	    return;
	}

	HDIB m_hDIB =::ReadDIBFile(cf);
	// 判断DIB是否为空
	if (m_hDIB != NULL)
	{
		LPSTR lpDIB = (LPSTR) ::GlobalLock((HGLOBAL) m_hDIB);
		
		// 获取DIB宽度
		int cxDIB = (int) ::DIBWidth(lpDIB);
		
		// 获取DIB高度
		int cyDIB = (int) ::DIBHeight(lpDIB);

		::GlobalUnlock((HGLOBAL) m_hDIB);
		
		CRect rcDIB;
		rcDIB.top = rcDIB.left = 0;
		rcDIB.right = cxDIB;
		rcDIB.bottom = cyDIB;
		
		CRect rcDest;
		
		// 判断是否是打印
		if (dc.IsPrinting())
		{
			// 是打印，计算输出图像的位置和大小，以便符合页面
			
			// 获取打印页面的水平宽度(象素)
			int cxPage = dc.GetDeviceCaps(HORZRES);
			
			// 获取打印页面的垂直高度(象素)
			int cyPage = dc.GetDeviceCaps(VERTRES);
			
			// 获取打印机每英寸象素数
			int cxInch = dc.GetDeviceCaps(LOGPIXELSX);
			int cyInch = dc.GetDeviceCaps(LOGPIXELSY);
			
			// 计算打印图像大小（缩放，根据页面宽度调整图像大小）
			rcDest.top = rcDest.left = 0;
			rcDest.bottom = (int)(((double)cyDIB * cxPage * cyInch)
					/ ((double)cxDIB * cxInch));
			rcDest.right = cxPage;
			
		// 计算打印图像位置（垂直居中）
			int temp = cyPage - (rcDest.bottom - rcDest.top);
			rcDest.bottom += temp/2;
			rcDest.top += temp/2;
		}
		else   
		// 非打印
		{
			CWAVELETApp *pApp=(CWAVELETApp *)AfxGetApp();
			int aa=pApp->mysize+1;
			rcDest.top = rcDest.left = 0;
			rcDest.right = cxDIB/aa;
			rcDest.bottom = cyDIB/aa;
		}
		
		// 输出DIB
		::PaintDIB(dc.m_hDC, &rcDest, m_hDIB,
			&rcDIB, m_palDIB);
	}
	
	// 恢复正常光标
	EndWaitCursor();
}