ASP.NET代码片段

设置下拉框的初始值：
  <asp:DropDownList ID="DropDownList1" runat="server">
        <asp:ListItem Text="小学" Value="1"></asp:ListItem>
        <asp:ListItem Text="中学" Value="2"></asp:ListItem>
        <asp:ListItem Text="大学" Value="3"></asp:ListItem>
        </asp:DropDownList>
 string init = "2";
            for (int i = 0; i < DropDownList1.Items.Count; i++)
            {
                if (DropDownList1.Items[i].Value.ToString() == init)
                {
                    DropDownList1.Items[i].Selected = true;
                }
            }
  
 DropDownList1.Items.Insert(0,new ListItem("选择类别",0));
<asp:GridView ID="GridView1" ShowFooter="false" BorderColor="Black" OnRowDataBound="GridView1_RowDataBound"  runat="server" AutoGenerateColumns="False"  Font-Size="12px" Width="549px"  AllowPaging="True" >
          <Columns>
            <asp:BoundField DataField="ID" HeaderText="编号" />
             <asp:BoundField DataField="EmpBirthday" HeaderText="生日" DataFormatString="{0:yyyy-MM-dd}" HtmlEncode="False" />
      &nbs