把常见的编码类型文件(ASCI、Unicode、utf-8)读出到std::string中

 

int VengConfig::GetFileType(LPCTSTR lpszFileName)
{
    CFile file;
    byte  buf[3]= {0};
    int tc;
    try
    {
        if(file.Open(lpszFileName,CFile::modeRead|CFile::shareDenyNone|CFile::typeBinary))
        {
            file.Read(buf,3);

            if(buf[0]==0xEF && buf[1]==0xBB && buf[2]==0xBF)
                tc=0;
            else if(buf[0]==0xFF && buf[1]==0xFE )
                tc=1 ;
            //else if(buf[0]==0xFE && buf[1]==0xFF )
            //    tc=sUNICODEBIGENDIAN;
            else
                tc=3;
        }
        else
            tc=4;
    }
    catch (CFileException ex)
    {
        CString errormsg;
        errormsg.Format(_T("操作文件%s时发生异常!"),ex.m_strFileName);
        cout<<errormsg<<endl;
    }

    return tc;
}

string VengConfig::AllFileDataTypeConventToString(string filepath,int nType)
{
    string FileData;
    FileData.empty();

    switch (nType)
    {
    case (3):
        {
            ifstream btfile(filepath.c_str(),ios::in|ios::binary);
            char buf[1024] = {0};
            ostringstream  osTempFileData;
            osTempFileData<<btfile.rdbuf();
            FileData = osTempFileData.str();
        }
        break;
    case 1:
        {
            FILE *pfile = NULL;
            errno_t erCode = fopen_s(&pfile,filepath.c_str(), "rb");

            fseek(pfile, 2, 0);
            wchar_t buf[1024]={0};
            wstring line;

            while (!feof(pfile))
            {
                fgetws(buf, 1024, pfile);
                line += buf;
            }
            fclose(pfile);

            DWORD dwNum = WideCharToMultiByte(CP_OEMCP,NULL,line.c_str(),-1,NULL,0,NULL,FALSE);
            PBYTE TmpBuf = new BYTE[dwNum];
            WideCharToMultiByte (CP_OEMCP,NULL,line.c_str(),-1,(PCHAR)TmpBuf,dwNum,NULL,FALSE);

            FileData = (PCHAR)TmpBuf;
            delete TmpBuf;
        }
        break;
    case  0:
        {
            wchar_t  buf[1024] = {0};
            FILE *fp = NULL;
            wstring line;
            _wfopen_s(&fp,CString(filepath.c_str()),_T("rt+,ccs=UTF-8"));
            locale loc("");
            wcout.imbue(loc);

            while(!feof(fp))
            {
                fgetws(buf,1024,fp);
                line += buf;
            }

            fclose(fp);
            DWORD dwNum = WideCharToMultiByte(CP_OEMCP,NULL,line.c_str(),-1,NULL,0,NULL,FALSE);
            PBYTE TmpBuf = new BYTE[dwNum];

            WideCharToMultiByte (CP_OEMCP,NULL,line.c_str(),-1,(PCHAR)TmpBuf,dwNum,NULL,FALSE);

            FileData = (PCHAR)TmpBuf;
            delete TmpBuf;
        }
        break;
    case  4:
        break;
    default:
        break;
    }

    return FileData;
}