MFC对话框使用CPrintDialog实现打印，指定打印机、后台打印

对话框打印，网上一搜一大堆，基本分2类：

A类： CPrintDialog.DoModal，然后在模态对话框里选打印机、打印配置；

B类：GetPrinterDeviceDefaults，调用默认打印机。

我的工作内容是理解以上2类后，再根据MSDN，实现MDF对话框后台指定打印机打印。

废话不多说，上菜~

功能：基于对话框的MFC打印（非文档视图结构），指定打印机，后台打印（不弹出对话框）

思路：

1、枚举打印机，并选择其中一个；

2、CPrintDialog实例指定到选中的打印机；

3、CPrintDialog后台打印

具体实现：

1、变量（控件）。在对话框上添加一个combobox（IDC_COMBO1，对应变量m_cboPrint）、一个edit（IDC_EDIT1），edit允许回车，多行（代码就不贴了，知道MFC应该就懂）；

2、在OnInitDialog里枚举打印机设备，如果报函数未定义，加入头文件#include <winspool.h>

需要调用两次EnumPrinters函数，第一次的到结构体的大小，第二次得到打印机列表

// TODO: 在此添加额外的初始化代码
	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、操作对话框，在IDC_EDIT1里输入打印的内容，在IDC_COMBO1里选中打印机；

4、打印（我是用OK按钮打印的，大家随便）

// TODO: 在此添加控件通知处理程序代码
//	CDialogEx::OnOK();
	this->UpdateData();

	CString strMessage;
	CString strPrintDevice;

	this->GetDlgItem(IDC_EDIT1)->GetWindowTextW(strMessage);
	strMessage += _T("\r\n");		//添加结尾，方便后面循环读取打印数据

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

	DWORD dwFlag = PD_ALLPAGES | PD_NOPAGENUMS | PD_USEDEVMODECOPIES | PD_HIDEPRINTTOFILE;	//打印配置界面的按钮可用性，因为后台打印，其实这个配置没什么意义

	CPrintDialog pPrintdlg(FALSE, dwFlag, this);											//CPrintDialog实例化，因为MFC的打印设备无关性，可以理解为这就是一台打印机

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

	strPrintDevice.ReleaseBuffer();

	pPrintdlg.m_pd.hDevMode = hDevMode;														//让pPrintdlg使用我们指定的打印机
	pPrintdlg.m_pd.hDevNames = hDevNames;

	CDC dc;
	dc.Attach(pPrintdlg.CreatePrinterDC());													//后台打印创建法，如果需要弹出打印对话框，请用DoModal

	DOCINFO di;																				//下面的内容网上很多，就不解释了
	di.cbSize = sizeof(DOCINFO);
	di.lpszDocName = _T("有驱打印测试");
	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("宋体"), &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);							//根据当前字体的宽、高，后面以此高度为行高

	while ((nIndex = strMessage.Find(_T("\r\n"))) > -1)					//将IDC_EDIT1编辑框中内容打印，支持换行，一次换行等于'\r\n'，所以在开头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，行高为字体高度
	}

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

关于GetPrinterDevice，来自微软的一篇文章， 点我跳转

代码也贴出来

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;
}

基本上是完整代码了，如果有内存错误，请联系我