由于种种需要直接进行读取Excel文件数据，然而在网上Search多次也没有找到好的方法，
一般就通过ODBC或OLE方式进行读取，但这两种方法都具有局限性...（我相信大家都很清楚）。
怎么办呢？没办法了，只好选择最艰难的路了--分析Excel文件格式。
 介绍
  MS Excel是众所周知的电子表格处理软件。Excel文件格式是特定的BIFF(Binary Interchange File Format)，BIFF里存储了很多记录，第条记录包括记录头和记录体。记录头是4byte，前两位指定记录类型的代码（opcode），后两位指定记录长度；记录体是存储该记录的实际数据。
比如：

BOF record
           |  Record Header    |    Record Body    |
Byte       |  0    1    2    3 |  0    1    2    3 |
           -----------------------------------------
Contents   | 09 | 00 | 04 | 00 | 02 | 00 | 10 | 00 |
           -----------------------------------------
           | opcode  | length  | version |  file   |
           |         |         |  number |  type   |
记录头：
    opcode: 09h is BOF;
    length: 04h record body is 4 bytes long;
记录体：
    version number:02h is version number (2 for the initial version of Excel)
    file type:10h is a worksheet file;
具体可参考MS Excel File Format。

 描述
以下是对本文程序简单描述。

      第一步：打开文件
    CFile f;
    CFileException e;

    // 打开文件
    if (!f.Open("D:\\Book1.xls", CFile::modeRead, &e))
    {
        TCHAR szError[1024];
        e.GetErrorMessage(szError, 1024);
        AfxMessageBox(szError);
        return;
    }
   

第二步：读取版本号
    // 读取版本
    while (dwPos < dwLen)
    {
        nRead = f.Read((void*)&RecNo, 2);
        if (RecNo == XL_BOF)   
        {
            WORD Ver, Type;
            f.Read((void*)&RecLen, 2);
            f.Read((void*)&Ver, 2);
            f.Read((void*)&Type, 2);
            f.Seek(RecLen, CFile::current);

            int ver = 0;
            switch (Ver)
            {
            case BIFF7:
                ver = 7;
                break;
            case BIFF8:
                ver = 8;
                AfxMessageBox("Biff8");
                break;
            }

            int type = 0;
            switch (Type)
            {
            case WORKBOOK:
                type = 5;
                AfxMessageBox("Workbook");
                break;
            case WORKSHEET:
                type = 16;
                AfxMessageBox("Worksheet");
                break;
            case CHART:
                type = 32;
                AfxMessageBox("Chart");
                break;
            }

            break;
        }
        dwPos = f.GetPosition();
    }   

第三步：读其它数据
    f.SeekToBegin();
    dwPos = f.GetPosition();
    // 读表格数据
    while (dwPos < dwLen)
    {
        nRead = f.Read((void*)&RecNo, 2);
        switch (RecNo)
        {
        case XL_BOF:
            {
                f.Read((void*)&RecLen, 2);
                AfxMessageBox("Bof");
            }
            break;
        case XL_BOUNDSHEET:
            {
                DWORD    temp;
                BYTE    visi;
                BYTE    type;
                TCHAR    name;
               
                f.Read((void*)&RecLen, 2);
                f.Read((void*)&temp, 4);
                f.Read((void*)&visi, 1);
                f.Read((void*)&type, 1);
                f.Read((void*)&StrLen, 2);
                f.Read((void*)&name, StrLen);
               
                char buf[128];
                memset(buf, 0x0, 128);
                strncpy(buf, &name, StrLen);
               
                AfxMessageBox(buf);
            }
            break;
        case XL_DIMENSION:
            f.Read((void*)&RecLen, 2);
            f.Seek(RecLen, CFile::current);
            AfxMessageBox("Dimension");
            break;
        case 0xE2:    // INTERFACED
            f.Read((void*)&RecLen, 2);
            AfxMessageBox("e2");
            break;
        case XL_SST:
            f.Read((void*)&RecLen, 2);
            f.Seek(RecLen, CFile::current);
            AfxMessageBox("SST");
            break;
        case XL_NUMBER:
            f.Read((void*)&RecLen, 2);
            AfxMessageBox("Number");
            break;
        case XL_STRING:
            f.Read((void*)&RecLen, 2);
            AfxMessageBox("String");
            break;
        case XL_RK:
            f.Read((void*)&RecLen, 2);
            AfxMessageBox("RK");
            break;
        case XL_LABEL:
            {
                f.Read((void*)&RecLen, 2);
                AfxMessageBox("Label");
            }
            break;
        case 0xD6:
            f.Read((void*)&RecLen, 2);
            AfxMessageBox("RString");
            break;
        case XL_EOF:
            dwPos = dwLen;
            AfxMessageBox("Eof");
            break;
        default:
            nRead = f.Read((void*)&RecLen, 2);
            if (nRead == 0)
                dwPos = dwLen;
            break;
        }
    }
    第四步：关闭文件
    f.Close();