识别文本文件编码格式

//识别编码函数 pathName 文件路径
CString CInsertKeyDlg::CodeTo(CString pathName)
{
char m_FileText[10000]={0};
CString m_NewText;
CFile m_File;
LPCTSTR lpstr = pathName.GetBuffer();
BOOL reBol = m_File.Open(lpstr, CFile::modeReadWrite,NULL);
m_File.Flush();
int a = (int)m_File.GetLength();
m_File.SeekToBegin();
m_File.Read(&m_FileText,a);

CString m_str,m_Code;
m_str.Format(_T("%x%x"),m_FileText[0]-m_FileText[0]-m_FileText[0],m_FileText[1]-m_FileText[1]-m_FileText[1]);
int m = ::StrToInt(m_str.GetBuffer());

switch(m)
{
//utf8
case 1145:
{
m_Code = _T("utf8");
break;
}
//unicode
case 12:
{
m_Code = _T("unicode");
break;
}
//ubigendian
case 21:
{
m_Code = _T("ubigendian");
break;
}
default :
{
m_Code = _T("ansi");
}
}


return m_Code;
}

//转换编码的函数目前只做了utf8，ansi不用转，默认就能读
CString CInsertKeyDlg::CodeToStr(CString strLine,CInsertKeyDlg *dlg)
{
if ( dlg->Code == _T("utf8") )
{
CString str;
CreateString_InitWithUTF8Text(str,UnicodeToAnsi(strLine.GetBuffer()));
strLine = str;
int a = strLine.Replace(_T("�?"),_T(""));
if(a)
{
strLine = strLine + _T("。");
strLine.Replace(_T("�"),_T(""));
}
}
else if ( dlg->Code == _T("unicode") )
{
USES_CONVERSION;
char* ch = W2A(strLine);
}
else if ( dlg->Code == _T("ubigendian") )
{

}

return strLine;
}