C / C++ / MFC

virtual BOOL WriteData(HANDLE hFile, LPOVERLAPPED pOverlapped, LPCSTR szBoundary=NULL, DWORD dwFlags = 0) throw()
	{	
		if (pOverlapped == NULL)
		{
			return FALSE;
		}

		// Make the MIME boundary for this message
		char szBoundaryBuf[ATL_MIME_BOUNDARYLEN+1];
		if(MakeBoundary(szBoundaryBuf,ATL_MIME_BOUNDARYLEN+1) == FALSE)
			return FALSE;

		// if the passed boundary is valid, this is an attached message
		if (szBoundary && *szBoundary != '\0')
		{
			_ATLTRY
			{
				// output the MIME header for a message attachment
				CStringA strHeader;
				strHeader.Format("\r\n\r\n--%s\r\nContent-Type: message/rfc822\r\n\tname=\"%s\"\r\nContent-Transfer-Encoding: 8bit\r\n"
					"Content-Disposition: attachment;\r\n\tfilename=\"%s\"\r\n\r\n", 
					szBoundary, m_szDisplayName, m_szDisplayName);

				if (!AtlSmtpSendAndWait(hFile, ((LPCSTR)strHeader), strHeader.GetLength(), pOverlapped))
				{
					return FALSE;
				}
			}
			_ATLCATCHALL()
			{
				return FALSE;
			}
		}

		if (!CMimeHeader::WriteData(hFile, pOverlapped, szBoundaryBuf, dwFlags))
			return FALSE;

		// Create and output the header
		CStringA strHeader;
		char szBoundaryBufTwo[ATL_MIME_BOUNDARYLEN+1];
		if (MakeMimeHeader(strHeader, szBoundaryBuf))
		{	
			MakeBoundary(szBoundaryBufTwo,ATL_MIME_BOUNDARYLEN+1);
			MakeMimeHeaderTwo(strHeader, szBoundaryBufTwo);
		}
		else
		{
			return FALSE;
		}

		if (!AtlSmtpSendAndWait(hFile, ((LPCSTR)strHeader), strHeader.GetLength(), pOverlapped))
		{
			return FALSE;
		}

		CMimeBodyPart* pCurrPart;
		POSITION currPos = m_BodyParts.GetHeadPosition();

		//Dump the body parts
		while (currPos != NULL)
		{
			pCurrPart = m_BodyParts.GetAt(currPos);
			if (pCurrPart->GetContentType()== "text/html"){
			if (!pCurrPart->WriteData(hFile, pOverlapped, szBoundaryBuf, dwFlags))
			{
				return FALSE;
			}
			m_BodyParts.GetNext(currPos);
			}
			else
			{
			if (!pCurrPart->WriteData(hFile, pOverlapped, szBoundaryBufTwo, dwFlags))
			{
				return FALSE;
			}
			m_BodyParts.GetNext(currPos);
			}
		}

		char szBuf[ATL_MIME_BOUNDARYLEN+(sizeof("\r\n\r\n--%s--\r\n"))];
		//output a trailing boundary
		if (*szBoundaryBuf)
		{
#if _SECURE_ATL
			int nBufLen = sprintf_s(szBuf, ATL_MIME_BOUNDARYLEN+(sizeof("\r\n\r\n--%s--\r\n")),
				"\r\n\r\n--%s--\r\n", szBoundaryBuf);
#else
			int nBufLen = _snprintf(szBuf, ATL_MIME_BOUNDARYLEN+(sizeof("\r\n\r\n--%s--\r\n")),
				"\r\n\r\n--%s--\r\n", szBoundaryBuf);
#endif
			if ((nBufLen < 0) || (!AtlSmtpSendAndWait(hFile, szBuf, nBufLen, pOverlapped)))
			{
				return FALSE;
			}
		}

		return TRUE;
	}

<br />
CFile file;<br />
file.Open("file.txt",CFile::modeRead);<br />
int len = file.GetLength();<br />
TCHAR pData = new TCHAR[len+1]; // +1 for terminating '\0'<br />
int read = file.Read(pData,(len+1)*sizeof(TCHAR));<br />
file[read] = '\0';<br />
// Could use CString in the following line, but what's the point?<br />
view_object.SetWindowText(pData);<br />
delete [] pData;<br />