关于SqlDataReader.

Question

问题:
我的界面上有两DropDownList控件,它们的数据源是一样的,都是来自于同一个SqlDataReader,但为什么只有其中一个有数据,另一个没有? 如下代码:SqlConnection myConnection = new SqlConnection(...);
String cmdText  ="SELECT ....";
SqlCommand myCommand = new SqlCommand(cmdText,myConnection);
myConnection.Open();
SqlDataReader recm = myCommand.ExecuteReader();
DropDownList1.DataSource = recm;
DropDownList1.DataTextField = "EmployeName";
DropDownList1.DataValueField="EmployeId";
DropDownList1.DataBind();
DropDownList2.DataSource = recm;
DropDownList2.DataTextField = "EmployeName";
DropDownList2.DataValueField="EmployeId";
DropDownList2.DataBind();我知道这种情况用SqlDataReader可能不合适,但我不知该用什么,大家有更好的建议吗?能不能写完整点的代码,因为我很菜的.

Answer 1

String cmdText  ="SELECT ....";
DataSet ds=GetDataSet(cmdText);DropDownList1.DataSource = ds;
DropDownList1.DataTextField = "EmployeName";
DropDownList1.DataValueField="EmployeId";
DropDownList1.DataBind();
DropDownList2.DataSource = ds;DropDownList2.DataTextField = "EmployeName";
DropDownList2.DataValueField="EmployeId";
DropDownList2.DataBind();//
public static DataSet GetDataSet(string sql)
{
     string ConnectionString="连接字符串";
            SqlDataAdapter    sda =new SqlDataAdapter(sql,ConnectionString);
            DataSet ds=new DataSet();
            sda.Fill(ds);
            return ds;
}

Answer 2

我实例中的完整代码如下:   SqlConnection myConnection = new SqlConnection(GlobalDB.DataBaseDB.ConnectionString);
   String cmdText = "SELECT DISTINCT RoomID FROM Room WHERE RoomBedMan is NULL OR RoomBedMan = 0 ORDER BY RoomID";
   myConnection.Open();
   SqlDataAdapter sdaRoom = new SqlDataAdapter(cmdText,myConnection);
   DataSet dsRoom = new DataSet();
   sdaRoom.Fill(dsRoom);
   addBedRoomID.DataSource = dsRoom;
   addBedRoomID.DataValueField = "RoomID";
   addBedRoomID.DataTextField = "RoomID";
   addBedRoomID.DataBind();
   ddlVacantRoom.DataSource = dsRoom;
   ddlVacantRoom.DataValueField = "RoomID";
   ddlVacantRoom.DataTextField = "RoomID";
   ddlVacantRoom.DataBind();
  }