public IList GetModelList(string tablename, string where)

          {

              IList list = null;

              DataTable dataTable = new DataTable();

              string sql = "select * from " + tablename;

              if (where != "")

              {

                  sql += " Where " + where;

              }

              try

              {

                  System.Data.SqlClient.SqlDataReader dr = DbHelperSQL.ExcuteReader(sql);

                  for (int i = ; i < dr.FieldCount; i++)

                  {

                      DataColumn mydc = new DataColumn();    //关键的一步

                      mydc.DataType = dr.GetFieldType(i);

                      mydc.ColumnName = dr.GetName(i);

                      dataTable.Columns.Add(mydc);          //关键的第二步

                  }

                  while (dr.Read())

                  {

                      DataRow mydr = dataTable.NewRow();     //关键的第三步

                      for (int i = ; i < dr.FieldCount; i++)

                      {

                          mydr[i] = dr[i].ToString();

                      }

                      dataTable.Rows.Add(mydr);            //关键的第四步

                      mydr = null;

                  }

                  dr.Close();

                  list = dataTable as IList;

                  return (list);

              }

              catch (Exception ex)

              {

                  throw ex;

              }

          }