DropDownList展示默认数据库值

DropDownList显示默认数据库值
问题如标题
T_DegreelevelControl.ascx里的代码如下

  protected void Page_Load(object sender, EventArgs e)
  {
   
  }

  override protected void OnInit(EventArgs e)
  {
  Bind();
  } 

  protected void Bind()
  {
  TeacherBLL DlevelA = new TeacherBLL();
  DropDownList1.DataSource =DlevelA.SelectAllDlevel();
  DropDownList1.DataValueField = "Dl_DlevelID";
  DropDownList1.DataTextField = "Dl_DlevelName";
  DropDownList1.DataBind();
  }

  public String Text
  {
  get
  {
  this.EnsureChildControls();
  return (DropDownList1.SelectedItem.Text);
  }
  set
  {
  this.EnsureChildControls();
  DropDownList1.SelectedItem.Text = value;
  }
  }
}


在前台写了
<%@ Register src="Control/T_DegreelevelControl.ascx" tagname="T_DegreelevelControl" tagprefix="uc5" %>
<td class="tableleft2">学历层次:</td>
<td class="tableleft2"><uc5:T_DegreelevelControl ID="T_DegreelevelControl2" runat="server" /></td>


后台代码
this.T_DegreelevelControl2.Text = Convert.ToString(ds.Tables[0].Rows[0]["T_Edegreelevel"]);

但这样显示出来的是DropDownList的第一项

请问该怎么修改才能显示默认数据库的值

[解决办法]
DropDownList1.SelectedIndex = "默认值Dl_DlevelID的值"
[解决办法]
修改selectindext值
[解决办法]
什么算是默认数据库的值啊？
[解决办法]
this.T_DegreelevelControl2.Items.FindByText(Convert.ToString(ds.Tables[0].Rows[0]["T_Edegreelevel"])).Selected = true;