无法解析的外部符号 "

控制台程序，main（）中定义了一个log文件记录实例：
CLogFile m_logfile;
CLogFile 类是从一个MFC程序移植过来的，
调用CLogFile 的WriteLog(CString LogText)，编译无错，连接错误

大神们帮小弟看看

error LNK2001: 无法解析的外部符号 "public: static bool __cdecl CLogFile::WriteLog(class ATL::CStringT<wchar_t,class ATL::StrTraitATL<wchar_t,class ATL::ChTraitsCRT<wchar_t> > >)" (?WriteLog@CLogFile@@SA_NV?$CStringT@_WV?$StrTraitATL@_WV?$ChTraitsCRT@_W@ATL@@@ATL@@@ATL@@@Z)

函数如下：
bool CLogFile::WriteLog(CString LogText)
{
try
{
// CFile m_File;
CStdioFile m_SFile;
CFileFind m_FileFind;
CString m_sErrorMessage;
CString m_sFileName = GetFileName();
CString m_sFilePath = GetFilePath();
CString m_sCurrentTime = CTime::GetCurrentTime().Format(L"%Y-%m-%d %X");
m_sErrorMessage = m_sCurrentTime + L" : ";
m_sErrorMessage += LogText + L"\r";
if(!m_FileFind.FindFile(m_sFilePath))
{
CreateDirectory(m_sFilePath,NULL);
}
if(!m_SFile.Open(m_sFilePath + "\\" +m_sFileName,CFile::modeReadWrite))
{
m_SFile.Open(m_sFilePath + "\\" + m_sFileName,CFile::modeCreate | CFile::modeReadWrite | CFile::typeText);
}
m_SFile.SeekToEnd();
m_SFile.Write(m_sErrorMessage,m_sErrorMessage.GetLength()*2);
m_SFile.Close();
}
catch(CFileException fileException)
{
return false;
}

return true;
}