Printing from CFormView

Download demo 54K

Printing from CFormView

There are several reasons for using a CFormView derived View Class, all of which are documented in the MFC documentation. As you may have found out, CFormView does not print the controls rendered in the View automatically. The code snippet below shows a quick way to get your CFormView application printing your screen, if that is all that you need. Please note, youll need a much better exception handling mechanism than my example. Nevertheless, this example demonstrates a quick way to get a printable CFormView View.
Our view class, called CPrintView is derived from CFormView; only 3 additional variables are needed to make CPrintView printable:
CDC * m_pMemDC;  //A memory device context compatible with our printer DC.
CRect m_rect;    //To hold the dimensions of our printing area while scaling.
CBitmap * m_pBm; //Capture the screen image as a Bitmap
Thats it. Lets see this in action:
In our views contructor, we initialize our variables:
CPrintView::CPrintView() : CFormView(CPrintView::IDD)
{	
	m_pMemDC = new CDC ;
	m_pBm = new CBitmap;
	
	//{{AFX_DATA_INIT(CPrintView)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT

}
Next we override CPrintView::OnBeginPrinting(..) as follows:
void CPrintView::OnBeginPrinting(CDC* pDC, CPrintInfo* /*pInfo*/)
{
	if (m_pMemDC->GetSafeHdc()) m_pMemDC->DeleteDC();
	m_pMemDC->CreateCompatibleDC(pDC);

	CClientDC dc(this);
	CRect rect;
	GetClientRect(rect);
	m_pMemDC->SetMapMode(MM_ANISOTROPIC);
	m_pMemDC->SetWindowExt(dc.GetDeviceCaps(LOGPIXELSX),dc.GetDeviceCaps(LOGPIXELSY));
	m_pMemDC->SetViewportExt(m_pMemDC->GetDeviceCaps(LOGPIXELSX),m_pMemDC->GetDeviceCaps(LOGPIXELSY));

	if (m_pBm->GetSafeHandle()) m_pBm->DeleteObject();
	m_pBm->CreateCompatibleBitmap(&dc,rect.Width(),rect.Height());
	m_pMemDC->SelectObject(m_pBm);
	dc.DPtoLP(rect); //Convert to Logical Coordinates
	m_rect = rect;   //Save Logical Coordinates
	m_pMemDC->BitBlt(0,0,rect.Width(),rect.Height(),&dc,0,0,SRCCOPY);
}
Next we need to override CPrintView::OnPrint(..)
void CPrintView::OnPrint(CDC* pDC, CPrintInfo*)
{
	//The Following code scales the image based on printer resolution.
	pDC->SetMapMode(MM_ANISOTROPIC);
	pDC->SetWindowExt(m_pMemDC->GetDeviceCaps(LOGPIXELSX),m_pMemDC->GetDeviceCaps(LOGPIXELSY));
	pDC->SetViewportExt(pDC->GetDeviceCaps(LOGPIXELSX),pDC->GetDeviceCaps(LOGPIXELSY));
	pDC->StretchBlt(0,0,m_rect.Width(),m_rect.Height(),m_pMemDC,0,0,m_rect.Width(),m_rect.Height(),SRCCOPY);

}
Lastly, we need to handle the destruction of our variables:
CPrintView::~CPrintView()
{
	delete m_pMemDC; //CLEAN UP OUR VARIABLES
	delete	m_pBm;
}
Thats it. Vinay Desai, Ph.D.

Note from section manager:
with this system you can print what is visible in the client area of the mainframe; it's a quick way to obtain a printed snapshot of the mainframe screen and so can have trouble with MDI formviews and cannot print what it's not show (if your formview is bigger than the mainframe, only portions will be printed; and that cannot be fixed with this approach). What is printed is influenced by the actual window size.

Last updated: 11 July 1998



Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • On-demand Event Event Date: September 10, 2014 Modern mobile applications connect systems-of-engagement (mobile apps) with systems-of-record (traditional IT) to deliver new and innovative business value. But the lifecycle for development of mobile apps is also new and different. Emerging trends in mobile development call for faster delivery of incremental features, coupled with feedback from the users of the app "in the wild." This loop of continuous delivery and continuous feedback is how the best mobile …

  • Java developers know that testing code changes can be a huge pain, and waiting for an application to redeploy after a code fix can take an eternity. Wouldn't it be great if you could see your code changes immediately, fine-tune, debug, explore and deploy code without waiting for ages? In this white paper, find out how that's possible with a Java plugin that drastically changes the way you develop, test and run Java applications. Discover the advantages of this plugin, and the changes you can expect to see …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds