Printing without the Document/View framework

Introduction

If you have a dialog based application and want to print, then you cannot take advantage of the Doc/View framework that MFC provides to do all the dirty work for you. The code presented below demonstrates the typical steps needed to:

• prompt the user for the printing characteristics such as printer and paper size (via a call to CPrintDialog::DoModal)
• Setup a printer DC and printing DOCINFO structure
• Use callbacks to adjust settings such as start and end pages to print, or printing sizes
• Print all pages to be printed
• Cleanup

The callbacks

In order to keep the MFC Doc/View feel I recomend providing helper callback functions OnBeginPrinting, OnEndPrinting and OnPrint similar to the CView versions. A CDC and a CPrintInfo object is passed into each of these functions. You will have to provide these functions yourself. Typically you would undertake any initialisation neessary (such as creating GDI objects) in OnBeginPrinting. Your OnPrint function would be where you do the actual printing/drawing, and your OnEndPrinting function performs any cleanup necessary (such as deleting GDI objects created in OnBeginPrinting). You can call these functions whatever you want - I've used these names to be consistant with the CView names, and they are only used to show where the various initialisation/printing/cleanup code should be inserted by you.

Typical implementations would look like:

void OnBeginPrinting(CDC *pDC, CPrintInfo* pInfo)
{
    // maybe pre cache some pens or brushes, or modify the
    // properties of the DC
}

void OnPrint(CDC *pDC, CPrintInfo* pInfo)
{
    // Do your drawing/printing exactly as you would in a
    // CView::OnDraw function. The CPrintInfo structure
    // will give you the bounds and the current page number
}

void OnEndPrinting(CDC *pDC, CPrintInfo* pInfo)
{
    // Clean up pens or brushes, or restore the DC
}

The Printing code

void CMyDialog::Print() 
{
    CDC dc;
    CPrintDialog printDlg(FALSE);

    if (printDlg.DoModal() == IDCANCEL)     // Get printer settings from user
        return;

    dc.Attach(printDlg.GetPrinterDC());     // Get and attach a printer DC
    dc.m_bPrinting = TRUE;

    CString strTitle;                       // Get the application title
    strTitle.LoadString(AFX_IDS_APP_TITLE);

    DOCINFO di;                             // Initialise print document details
    ::ZeroMemory (&di, sizeof (DOCINFO));
    di.cbSize = sizeof (DOCINFO);
    di.lpszDocName = strTitle;

    BOOL bPrintingOK = dc.StartDoc(&di);    // Begin a new print job

    // Get the printing extents and store in the m_rectDraw field of a 
    // CPrintInfo object
    CPrintInfo Info;
    Info.m_rectDraw.SetRect(0,0, 
                            dc.GetDeviceCaps(HORZRES), 
                            dc.GetDeviceCaps(VERTRES));

    OnBeginPrinting(&dc, &Info);            // Call your "Init printing" function
    for (UINT page = Info.GetMinPage(); 
         page <= Info.GetMaxPage() && bPrintingOK; 
         page++)
    {
        dc.StartPage();                     // begin new page
        Info.m_nCurPage = page;
        OnPrint(&dc, &Info);                // Call your "Print page" function
        bPrintingOK = (dc.EndPage() > 0);   // end page
    }
    OnEndPrinting(&dc, &Info);              // Call your "Clean up" function

    if (bPrintingOK)
        dc.EndDoc();                        // end a print job
    else
        dc.AbortDoc();                      // abort job.

    dc.DeleteDC();                          // delete the printer DC
}