关于dataset的 一些杂碎点

            string connstr = "Data Source=.;Initial Catalog=DB_LMS;Integrated Security=True";
            string sqlstr = "select * from tb_BookMess";
            SqlDataAdapter ad = new SqlDataAdapter(sqlstr, connstr);

            DataSet ds = new DataSet();
            ad.Fill(ds, "tb_BookMess");
                     

             /////获得表的列名

                ds.Tables["tb_BookMess"].Columns[i].ToString() ;

             ////获得表的某行某列的值
            string str= ds.Tables["tb_BookMess"].Rows[0][2].ToString();