数据库查找数据绑定到DropList上

//获得学科列表
DataTable xiaoXueke = My_Sql.Sql5("select X_SN,X_DaiMa,X_Name from NongCun_XueKe");
this.Drop_XueKe.DataSource = xiaoXueke;
this.Drop_XueKe.DataTextField = "X_Name";
this.Drop_XueKe.DataValueField = "X_DaiMa";
this.Drop_XueKe.DataBind();
DataRow[] _XueKe = xiaoXueke.Select();
for (int i = 0; i < _XueKe.Length;i++ )
{
this.Drop_XueKe.Items.Add(new ListItem("学科："+_XueKe[i]["X_name"].ToString(),_XueKe[i]["X_DaiMa"].ToString()));
}