Datalist selectIndex更改事件未触发

Question

这是我的DataList：

   <asp:DataList ID="DataList1" runat="server" RepeatColumns="4" RepeatDirection="Horizontal"
                 OnSelectedIndexChanged="DataList1_SelectedIndexChanged" CommandName="Select">
                <ItemTemplate>
                    <asp:Panel ID="Panel1" runat="server">
                        <table>
                            <tr >
                                <td >
                                    <asp:ImageButton CssClass="img" ID="imgProduct" runat="server" ImageUrl='<%#Eval("StudentPics") %>'></asp:ImageButton>
                                </td>
                            </tr>
                            <tr >
                                <td >
                                    <asp:TextBox ID="idtxt" runat="server" Text='<%# Eval("id") %>' Visible="false"></asp:TextBox>

                                </td>
                            </tr>
                        </table>
                    </asp:Panel>

                </ItemTemplate>
            </asp:DataList>

这是我的代码：

public partial class ClassTouch4 : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {

            datalistbind();

        }

    }


    protected void datalistbind()
    {
       //binding operation done !!!
    }

    protected void DataList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        DataList1.SelectedItem.BackColor = Color.Red;
    }
}

我将DataBind()放入(!IsPostBack)，我尝试了CommandName="select"，但它仍无效。我也尝试了其他解决方案，但selectedIndexChanged没有解雇。我缺少什么？