MFC對話框使用CPrintDialog實現打印，指定打印機、後臺打印

對話框打印，網上一搜一大堆，基本分2類：

A類： CPrintDialog.DoModal，然後在模態對話框裏選打印機、打印配置；

B類：GetPrinterDeviceDefaults，調用默認打印機。

我的工作內容是理解以上2類後，再根據MSDN，實現MDF對話框後臺指定打印機打印。

廢話不多說，上菜~

功能：基於對話框的MFC打印（非文檔視圖結構），指定打印機，後臺打印（不彈出對話框）

思路：

1、枚舉打印機，並選擇其中一個；

2、CPrintDialog實例指定到選中的打印機；

3、CPrintDialog後臺打印

具體實現：

1、變量（控件）。在對話框上添加一個combobox（IDC_COMBO1，對應變量m_cboPrint）、一個edit（IDC_EDIT1），edit允許回車，多行（代碼就不貼了，知道MFC應該就懂）；

2、在OnInitDialog裏枚舉打印機設備，如果報函數未定義，加入頭文件#include <winspool.h>

需要調用兩次EnumPrinters函數，第一次的到結構體的大小，第二次得到打印機列表

// TODO: 在此添加額外的初始化代碼
	DWORD dwNeeded;
	DWORD dwReturn;
	DWORD dwFlag = PRINTER_ENUM_CONNECTIONS | PRINTER_ENUM_LOCAL;

	EnumPrinters(dwFlag, NULL, 4, NULL, 0, &dwNeeded, &dwReturn);

	PRINTER_INFO_4* p4;
	p4 = new PRINTER_INFO_4[dwNeeded];
	EnumPrinters(dwFlag, NULL, 4, (PBYTE)p4, dwNeeded, &dwNeeded, &dwReturn);

	for (int i = 0; i<(int)dwReturn; i++)
		this->m_cboPrint.AddString(p4[i].pPrinterName);

	delete []p4;

3、操作對話框，在IDC_EDIT1裏輸入打印的內容，在IDC_COMBO1裏選中打印機；

4、打印（我是用OK按鈕打印的，大家隨便）

// TODO: 在此添加控件通知處理程序代碼
//	CDialogEx::OnOK();
	this->UpdateData();

	CString strMessage;
	CString strPrintDevice;

	this->GetDlgItem(IDC_EDIT1)->GetWindowTextW(strMessage);
	strMessage += _T("\r\n");		//添加結尾，方便後面循環讀取打印數據

	this->GetDlgItem(IDC_COMBO1)->GetWindowTextW(strPrintDevice);

	DWORD dwFlag = PD_ALLPAGES | PD_NOPAGENUMS | PD_USEDEVMODECOPIES | PD_HIDEPRINTTOFILE;	//打印配置界面的按鈕可用性，因爲後臺打印，其實這個配置沒什麼意義

	CPrintDialog pPrintdlg(FALSE, dwFlag, this);											//CPrintDialog實例化，因爲MFC的打印設備無關性，可以理解爲這就是一臺打印機

	HGLOBAL hDevMode = NULL;
	HGLOBAL hDevNames = NULL;
	if (GetPrinterDevice(strPrintDevice.GetBuffer(0), &hDevNames, &hDevMode))				//獲得指定打印機的配置、名字
		AfxGetApp()->SelectPrinter(hDevNames, hDevMode);
	else
		AfxMessageBox(_T("Failed to select custom printer"));

	strPrintDevice.ReleaseBuffer();

	pPrintdlg.m_pd.hDevMode = hDevMode;														//讓pPrintdlg使用我們指定的打印機
	pPrintdlg.m_pd.hDevNames = hDevNames;

	CDC dc;
	dc.Attach(pPrintdlg.CreatePrinterDC());													//後臺打印創建法，如果需要彈出打印對話框，請用DoModal

	DOCINFO di;																				//下面的內容網上很多，就不解釋了
	di.cbSize = sizeof(DOCINFO);
	di.lpszDocName = _T("有驅打印測試");
	di.lpszDatatype = NULL;
	di.lpszOutput = NULL;
	di.fwType = 0;

	dc.StartDocW(&di);
	dc.StartPage();
	dc.SetMapMode(MM_TEXT);

	CRect recPrint(0, 0, dc.GetDeviceCaps(LOGPIXELSX), dc.GetDeviceCaps(LOGPIXELSY));
	dc.DPtoLP(&recPrint);
	dc.SetWindowOrg(0, 0);

	CFont newFont;
	VERIFY(newFont.CreatePointFont(120, _T("宋體"), &dc));
	CFont* oldFont = dc.SelectObject(&newFont);

	dc.SetTextAlign(TA_TOP | TA_LEFT);

	CString strPrint;
	int nIndex = 0;
	int x = 50;
	int y = 50;
	CSize textSize;
	textSize = dc.GetTextExtent(_T("00"), 2);							//根據當前字體的寬、高，後面以此高度爲行高

	while ((nIndex = strMessage.Find(_T("\r\n"))) > -1)					//將IDC_EDIT1編輯框中內容打印，支持換行，一次換行等於'\r\n'，所以在開頭strMessage += _T("\r\n")
	{
		strPrint = strMessage.Left(nIndex);
		strMessage = strMessage.Mid(nIndex+2);

		dc.TextOutW(x, y, strPrint);

		y += textSize.cy;												//下移一行，行高爲字體高度
	}

	dc.SelectObject(oldFont);
	newFont.DeleteObject();
	dc.EndPage();
	dc.EndDoc();
	DeleteDC(dc.Detach());

關於GetPrinterDevice，來自微軟的一篇文章，點我跳轉

代碼也貼出來

BOOL CMFCApplication2Dlg::GetPrinterDevice(LPTSTR pszPrinterName, HGLOBAL* phDevNames, HGLOBAL* phDevMode)
{
	// if NULL is passed, then assume we are setting app object's
	// devmode and devnames
	if (phDevMode == NULL || phDevNames == NULL)
		return FALSE;

	// Open printer
	HANDLE hPrinter;
	if (OpenPrinter(pszPrinterName, &hPrinter, NULL) == FALSE)
		return FALSE;

	// obtain PRINTER_INFO_2 structure and close printer
	DWORD dwBytesReturned, dwBytesNeeded;
	GetPrinter(hPrinter, 2, NULL, 0, &dwBytesNeeded);
	PRINTER_INFO_2* p2 = (PRINTER_INFO_2*)GlobalAlloc(GPTR,
		dwBytesNeeded);
	if (GetPrinter(hPrinter, 2, (LPBYTE)p2, dwBytesNeeded,
		&dwBytesReturned) == 0) {
			GlobalFree(p2);
			ClosePrinter(hPrinter);
			return FALSE;
	}
	ClosePrinter(hPrinter);

	// Allocate a global handle for DEVMODE
	HGLOBAL  hDevMode = GlobalAlloc(GHND, sizeof(*p2->pDevMode) +
		p2->pDevMode->dmDriverExtra);
	ASSERT(hDevMode);
	DEVMODE* pDevMode = (DEVMODE*)GlobalLock(hDevMode);
	ASSERT(pDevMode);

	// copy DEVMODE data from PRINTER_INFO_2::pDevMode
	memcpy(pDevMode, p2->pDevMode, sizeof(*p2->pDevMode) +
		p2->pDevMode->dmDriverExtra);
	GlobalUnlock(hDevMode);

	// Compute size of DEVNAMES structure from PRINTER_INFO_2's data
	DWORD drvNameLen = lstrlen(p2->pDriverName)+1;  // driver name
	DWORD ptrNameLen = lstrlen(p2->pPrinterName)+1; // printer name
	DWORD porNameLen = lstrlen(p2->pPortName)+1;    // port name

	// Allocate a global handle big enough to hold DEVNAMES.
	HGLOBAL hDevNames = GlobalAlloc(GHND,
		sizeof(DEVNAMES) +
		(drvNameLen + ptrNameLen + porNameLen)*sizeof(TCHAR));
	ASSERT(hDevNames);
	DEVNAMES* pDevNames = (DEVNAMES*)GlobalLock(hDevNames);
	ASSERT(pDevNames);

	// Copy the DEVNAMES information from PRINTER_INFO_2
	// tcOffset = TCHAR Offset into structure
	int tcOffset = sizeof(DEVNAMES)/sizeof(TCHAR);
	ASSERT(sizeof(DEVNAMES) == tcOffset*sizeof(TCHAR));

	pDevNames->wDriverOffset = tcOffset;
	memcpy((LPTSTR)pDevNames + tcOffset, p2->pDriverName,
		drvNameLen*sizeof(TCHAR));
	tcOffset += drvNameLen;

	pDevNames->wDeviceOffset = tcOffset;
	memcpy((LPTSTR)pDevNames + tcOffset, p2->pPrinterName,
		ptrNameLen*sizeof(TCHAR));
	tcOffset += ptrNameLen;

	pDevNames->wOutputOffset = tcOffset;
	memcpy((LPTSTR)pDevNames + tcOffset, p2->pPortName,
		porNameLen*sizeof(TCHAR));
	pDevNames->wDefault = 0;

	GlobalUnlock(hDevNames);
	GlobalFree(p2);   // free PRINTER_INFO_2

	// set the new hDevMode and hDevNames
	*phDevMode = hDevMode;
	*phDevNames = hDevNames;
	return TRUE;
}

基本上是完整代碼了，如果有內存錯誤，請聯繫我