用OLEDB通过设置连接字符串可以像读取sqlserver一样将excel中的数据读取出来，但是excel和excel/的连接字符串是不同的。
/// <summary>/// 把数据从Excel装载到DataTable/// </summary>/// <param name="pathName">带路径的Excel文件名</param>/// <param name="sheetName">工作表名</param>/// <param name="tbContainer">将数据存入的DataTable</param>/// <returns></returns>public DataTable ExcelToDataTable(string pathName, string sheetName){DataTable tbContainer = new DataTable();string strConn = string.Empty;if (string.IsNullOrEmpty(sheetName)) { sheetName = "Sheet1"; }FileInfo file = new FileInfo(pathName);if (!file.Exists) { throw new Exception("文件不存在"); }string extension = file.Extension;switch (extension){case ".xls":strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";break;case ".xlsx":strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + pathName + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1;'";break;default:strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";break;}//链接ExcelOleDbConnection cnnxls = new OleDbConnection(strConn);//读取Excel里面有 表Sheet1OleDbDataAdapter oda = new OleDbDataAdapter(string.Format("select * from [{0}$]", sheetName), cnnxls);DataSet ds = new DataSet();//将Excel里面有表内容装载到内存表中！oda.Fill(tbContainer);return tbContainer;}
这里需要注意的地方是，当文件的后缀名为.xlsx(excel/)时的连接字符串是"Provider=Microsoft.ACE.OLEDB.12.0;...."，注意中间红色部分不是"Jet"。
