MFC - Printing a CBitmap to printer CDC - printing

Question

I am using the following code to print what is inside the clipboard (bitmap).
On the printed paper, I see the black line drawn with MoveTo/LineTo however the bitmap is not drawn.
Using the same drawing code in a CView works perfectly fine.
keybd_event(VK_SNAPSHOT, 1, 0, NULL);
HBITMAP handle = NULL;
if (::OpenClipboard(NULL))
{
handle = (HBITMAP)GetClipboardData(CF_BITMAP);
if (handle)
{
CBitmap* pBmp = CBitmap::FromHandle(handle);
BITMAP bm;
pBmp->GetBitmap(&bm);
int iBmpWidth = bm.bmWidth;
int iBmpHeight = bm.bmHeight;
CPrintDialog* pDlg = new CPrintDialog(FALSE);
CString csText;
CString cTitle;
if (pDlg->GetDefaults() == FALSE)
{
delete pDlg;
return;
}
pDlg->m_pd.Flags &= ~PD_RETURNDEFAULT;
LPDEVMODE pDevMode = pDlg->GetDevMode();
::GlobalUnlock(pDlg->m_pd.hDevMode);
DOCINFO di;
di.cbSize = sizeof(DOCINFO);
pDlg->m_pd.hwndOwner = this->GetSafeHwnd();
if (pDlg->DoModal() == IDOK)
{
HDC hdcPrinter = pDlg->GetPrinterDC();
if (hdcPrinter != NULL)
{
pDevMode = (LPDEVMODE)GlobalLock(pDlg->m_pd.hDevMode);
pDevMode->dmPaperSize = DMPAPER_A4;
pDevMode->dmOrientation = DMORIENT_LANDSCAPE;
ResetDCW(hdcPrinter, pDevMode);
GlobalUnlock(pDlg->m_pd.hDevMode);
// create a CDC and attach it to the default printer
CDC dcPrinter;
dcPrinter.Attach(hdcPrinter);
// call StartDoc() to begin printing
DOCINFO docinfo;
memset(&docinfo, 0, sizeof(docinfo));
docinfo.cbSize = sizeof(docinfo);
docinfo.lpszDocName = _T("CDC::StartDoc() Code Fragment");
// if it fails, complain and exit gracefully
if (dcPrinter.StartDoc(&docinfo) < 0)
{
MessageBox(_T("Printer wouldn't initalize"));
}
else
{
// start a page
if (dcPrinter.StartPage() < 0)
{
MessageBox(_T("Could not start page"));
dcPrinter.AbortDoc();
}
else
{
int PaperWidth = dcPrinter.GetDeviceCaps(HORZRES);
int PaperHeight = dcPrinter.GetDeviceCaps(VERTRES);
CDC memDC;
memDC.CreateCompatibleDC(&dcPrinter);
CBitmap* pOldBit = memDC.SelectObject(pBmp);
dcPrinter.MoveTo(1000, 1000);
dcPrinter.LineTo(PaperWidth - 1000, PaperHeight - 1000);
dcPrinter.StretchBlt(100,
100,
PaperWidth - 100,
PaperHeight - 100,
&memDC,
0,
0,
iBmpWidth,
iBmpHeight,
SRCCOPY);
memDC.SelectObject(pOldBit);
memDC.DeleteDC();
dcPrinter.EndPage();
dcPrinter.EndDoc();
}
}
}
}
delete pDlg;
}
::EmptyClipboard();
::CloseClipboard();
}

Answer 1

Using your code without any changes works for me, I tested using a real printer and CutePDF, both printed the bitmap. It might be an issue with your source DC when you create memDC, either it does not support the correct color space or does not support raster operations. Try the following code instead:
CDC* pDC = GetDesktopWindow()->GetDC();
memDC.CreateCompatibleDC(pDC);
GetDesktopWindow()->ReleaseDC(pDC);