添加命名空间：using System.Data.OleDb; /// 
        /// 从excel表格加载数据返回DataSet        /// 
        /// excel路径        /// 查询excel的sql命令，为“”或null默认查询Sheet1表        /// 
     
      返回DataSet
             public static DataSet LoadFromExcel(string path,string sql_Command)        {            string strConn;            /*              HDR=NO: 第一行也作为数据行              IMEX=1: 把所有列都做为字符串来读取             */            strConn = @"Provider=Microsoft.Ace.OleDb.12.0;" + "data source=" + path +                 ";Extended Properties='Excel 12.0; HDR=NO; IMEX=1'"; //此連接可以操作.xls與.xlsx文件/此連接可以操作.xls與.xlsx文件            OleDbConnection oleConn = new OleDbConnection(strConn);            DataSet ds = new DataSet();            if (sql_Command == null || sql_Command == "")            {                try                {                    oleConn.Open();                    string sql = "select * from [Sheet1$]";                    OleDbDataAdapter adapter = new OleDbDataAdapter(sql, oleConn);                    adapter.Fill(ds);                    return ds;                }                catch                {                    throw new Exception("加载失败！");                }                finally                {                    oleConn.Close();                }            }            else            {                oleConn.Open();                OleDbDataAdapter adapter = new OleDbDataAdapter(sql_Command, oleConn);                adapter.Fill(ds);                return ds;            }                  }