ADO.NET操作Excel的连接字符串

 private string GetConnectionString(string filePath)
        {
            if (filePath.EndsWith(".xls"))
                return string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};"
                    +"Extended Properties='Excel 8.0;HDR=Yes;IMEX=2';", filePath);
            if (filePath.EndsWith(".xlsx"))
                return string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};"
                    + "Extended Properties='Excel 12.0 Xml;HDR=YES';", filePath);
            throw new Exception("wrong file type!");
        }