不让DropDownList刷新页面，但OnSelectedIndexChanged事件需要触发，怎样实现

Question

<asp:DropDownList ID="DDL_Type" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DDL_Type_SelectedIndexChanged">
                                </asp:DropDownList>
protected void DDL_Type_SelectedIndexChanged(object sender, EventArgs e)
    {        if (Convert.ToInt32(this.DDL_Type.SelectedValue) > 0)
        {
            TProductType type = new TProductType("");
            this.DDL_DetaiType.DataSource = type.GetList1(Convert.ToInt16(this.DDL_Type.SelectedValue));
            this.DDL_DetaiType.DataValueField = "FID";
            this.DDL_DetaiType.DataTextField = "FTypeName";
            this.DDL_DetaiType.DataBind();
            UpdatePanelNewPerAssetReg.Update();        }
    }不让dropdownlist刷新页面，但是OnSelectedIndexChanged还要触发，怎样实现，请大家帮帮忙

Answer 1

dropdownlist在UpdatePanel里边了，可是不行

Answer 2

<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager><asp:UpdatePanel ID="" runat="">
<ContentTemplate>
   <asp:DropDownList ID="DDL_Type" runat="server"AutoPostBack="true"OnSelectedIndexChanged="DDL_Type_SelectedIndexChanged">
  </asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>