急：MFC是在哪里设置CPrintInfo的pInfo的？

[rick29]

如果要在OnPreparePrinting()调用之前改变pInfo,应放在哪里？

[rick29]

没人知道啊？

[cloudshadow1]

如果要在OnPreparePrinting()中设置pInfo,你就一定要重载你的视图类的OnFilePrint()了，因为是在CWnd定义了这个函数，并设置了pInfo,具体的做法是在调试时得到了CWnd::OnFilePrint()的代码，然后COPY下来，用于重载你自已的OnFilePrint().以下是CWnd::OnFilePrint()的代码：
void CView::OnFilePrint()
{
// get default print info
CPrintInfo printInfo;
ASSERT(printInfo.m_pPD != NULL); // must be set

if (LOWORD(GetCurrentMessage()->wParam) == ID_FILE_PRINT_DIRECT)
{
CCommandLineInfo* pCmdInfo = AfxGetApp()->m_pCmdInfo;

if (pCmdInfo != NULL)
{
if (pCmdInfo->m_nShellCommand == CCommandLineInfo::FilePrintTo)
{
printInfo.m_pPD->m_pd.hDC = ::CreateDC(pCmdInfo->m_strDriverName,
pCmdInfo->m_strPrinterName, pCmdInfo->m_strPortName, NULL);
if (printInfo.m_pPD->m_pd.hDC == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}
}
}

printInfo.m_bDirect = TRUE;
}

if (OnPreparePrinting(&printInfo))
{
// hDC must be set (did you remember to call DoPreparePrinting?)
ASSERT(printInfo.m_pPD->m_pd.hDC != NULL);

// gather file to print to if print-to-file selected
CString strOutput;
if (printInfo.m_pPD->m_pd.Flags & PD_PRINTTOFILE && !printInfo.m_bDocObject)
{
// construct CFileDialog for browsing
CString strDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULTEXT));
CString strPrintDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULT));
CString strFilter(MAKEINTRESOURCE(AFX_IDS_PRINTFILTER));
CString strCaption(MAKEINTRESOURCE(AFX_IDS_PRINTCAPTION));
CFileDialog dlg(FALSE, strDef, strPrintDef,
OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT, strFilter);
dlg.m_ofn.lpstrTitle = strCaption;

if (dlg.DoModal() != IDOK)
return;

// set output device to resulting path name
strOutput = dlg.GetPathName();
}

// set up document info and start the document printing process
CString strTitle;
CDocument* pDoc = GetDocument();
if (pDoc != NULL)
strTitle = pDoc->GetTitle();
else
GetParentFrame()->GetWindowText(strTitle);
if (strTitle.GetLength() > 31)
strTitle.ReleaseBuffer(31);
DOCINFO docInfo;
memset(&docInfo, 0, sizeof(DOCINFO));
docInfo.cbSize = sizeof(DOCINFO);
docInfo.lpszDocName = strTitle;
CString strPortName;
int nFormatID;
if (strOutput.IsEmpty())
{
docInfo.lpszOutput = NULL;
strPortName = printInfo.m_pPD->GetPortName();
nFormatID = AFX_IDS_PRINTONPORT;
}
else
{
docInfo.lpszOutput = strOutput;
AfxGetFileTitle(strOutput,
strPortName.GetBuffer(_MAX_PATH), _MAX_PATH);
nFormatID = AFX_IDS_PRINTTOFILE;
}

// setup the printing DC
CDC dcPrint;
if (!printInfo.m_bDocObject)
{
dcPrint.Attach(printInfo.m_pPD->m_pd.hDC); // attach printer dc
dcPrint.m_bPrinting = TRUE;
}
OnBeginPrinting(&dcPrint, &printInfo);

if (!printInfo.m_bDocObject)
dcPrint.SetAbortProc(_AfxAbortProc);

// disable main window while printing & init printing status dialog
AfxGetMainWnd()->EnableWindow(FALSE);
CPrintingDialog dlgPrintStatus(this);

CString strTemp;
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_DOCNAME, strTitle);
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PRINTERNAME,
printInfo.m_pPD->GetDeviceName());
AfxFormatString1(strTemp, nFormatID, strPortName);
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PORTNAME, strTemp);
dlgPrintStatus.ShowWindow(SW_SHOW);
dlgPrintStatus.UpdateWindow();

// start document printing process
if (!printInfo.m_bDocObject && dcPrint.StartDoc(&docInfo) == SP_ERROR)
{
// enable main window before proceeding
AfxGetMainWnd()->EnableWindow(TRUE);

// cleanup and show error message
OnEndPrinting(&dcPrint, &printInfo);
dlgPrintStatus.DestroyWindow();
dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}

// Guarantee values are in the valid range
UINT nEndPage = printInfo.GetToPage();
UINT nStartPage = printInfo.GetFromPage();

if (nEndPage < printInfo.GetMinPage())
nEndPage = printInfo.GetMinPage();
if (nEndPage > printInfo.GetMaxPage())
nEndPage = printInfo.GetMaxPage();

if (nStartPage < printInfo.GetMinPage())
nStartPage = printInfo.GetMinPage();
if (nStartPage > printInfo.GetMaxPage())
nStartPage = printInfo.GetMaxPage();

int nStep = (nEndPage >= nStartPage) ? 1 : -1;
nEndPage = (nEndPage == 0xffff) ? 0xffff : nEndPage + nStep;

VERIFY(strTemp.LoadString(AFX_IDS_PRINTPAGENUM));

// If it's a doc object, we don't loop page-by-page
// because doc objects don't support that kind of levity.

BOOL bError = FALSE;
if (printInfo.m_bDocObject)
{
OnPrepareDC(&dcPrint, &printInfo);
OnPrint(&dcPrint, &printInfo);
}
else
{
// begin page printing loop
for (printInfo.m_nCurPage = nStartPage;
printInfo.m_nCurPage != nEndPage; printInfo.m_nCurPage += nStep)
{
OnPrepareDC(&dcPrint, &printInfo);

// check for end of print
if (!printInfo.m_bContinuePrinting)
break;

// write current page
TCHAR szBuf[80];
wsprintf(szBuf, strTemp, printInfo.m_nCurPage);
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PAGENUM, szBuf);

// set up drawing rect to entire page (in logical coordinates)
printInfo.m_rectDraw.SetRect(0, 0,
dcPrint.GetDeviceCaps(HORZRES),
dcPrint.GetDeviceCaps(VERTRES));
dcPrint.DPtoLP(&printInfo.m_rectDraw);

// attempt to start the current page
if (dcPrint.StartPage() < 0)
{
bError = TRUE;
break;
}

// must call OnPrepareDC on newer versions of Windows because
// StartPage now resets the device attributes.
if (afxData.bMarked4)
OnPrepareDC(&dcPrint, &printInfo);

ASSERT(printInfo.m_bContinuePrinting);

// page successfully started, so now render the page
OnPrint(&dcPrint, &printInfo);
if (dcPrint.EndPage() < 0 || !_AfxAbortProc(dcPrint.m_hDC, 0))
{
bError = TRUE;
break;
}
}
}

// cleanup document printing process
if (!printInfo.m_bDocObject)
{
if (!bError)
dcPrint.EndDoc();
else
dcPrint.AbortDoc();
}

AfxGetMainWnd()->EnableWindow(); // enable main window

OnEndPrinting(&dcPrint, &printInfo); // clean up after printing
dlgPrintStatus.DestroyWindow();

dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
}
}

[rick29]

谢了！我去试试。

[rick29]

ok,我想我知道怎么做了！谢谢！不过，我重载派生VIEW类的OnFilePrint()时，其中并未调用基类的OnFilePrint(),那调试的时候如何跟踪到CView::OnFilePrint()呢？还望教我一手。