No updatemode with detailview in updatepanel

Hello,

I have a detail view in a updatepanel. The trigger is a treeview. When i want to update the data a can't see anything.

*.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/AdminSite.Master" AutoEventWireup="true" CodeBehind="WetTekstEdit.aspx.cs" Inherits="Bouwgegevens.nl.Sitemanager.WetTekstEdit" %><%@ Register Assembly="CKEditor.NET" Namespace="CKEditor.NET" TagPrefix="CKEditor" %><asp:Content ID="Content1" ContentPlaceHolderID="cphHeaderContent" runat="server"></asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="cphMainContent" runat="server"><h1>Wettekst Aanpassen</h1><div id="dvWetAanpassen"><asp:DropDownList ID="ddlWettekst" runat="server" AppendDataBoundItems="true" AutoPostBack="true" DataSourceID="edsDdlWetTekst" 
            DataTextField="TitelWet" DataValueField="WetID"><asp:ListItem Text="Kies een Wet" Value="0" /></asp:DropDownList><br /><br /><asp:EntityDataSource runat="server" ID="edsDdlWetTekst" DefaultContainerName="DBBouwgegevensEntities"
            ConnectionString="name=DBBouwgegevensEntities" EnableFlattening="False" EntitySetName="tbl_Wetten"
            Select="it.[WetID], it.[TitelWet]" EntityTypeFilter="tbl_Wetten"></asp:EntityDataSource><table class="tblWetTekst"><tr><td class="tdWetMenuHeader"><asp:DetailsView ID="dtvWet" runat="server" CssClass="dtvWetTekst"
                    AutoGenerateRows="False" RowStyle-VerticalAlign="NotSet" GridLines="None"
                    BorderWidth="0px" BorderStyle="None" DataSourceID="edsWet" ><Fields><asp:TemplateField ShowHeader="False"  SortExpression="TitelWet"><ItemTemplate><h3><asp:Label runat="server" Text='<%# Bind("TitelWet") %>' ID="Label1"></asp:Label></h3></ItemTemplate></asp:TemplateField></Fields></asp:DetailsView><asp:EntityDataSource runat="server" ID="edsWet" DefaultContainerName="DBBouwgegevensEntities"
                    ConnectionString="name=DBBouwgegevensEntities" EnableFlattening="False" EntitySetName="tbl_Wetten"
                    EntityTypeFilter="tbl_Wetten" Select="it.[WetID], it.[TitelWet]" Where="it.[WetID] = @WetID"><SelectParameters><asp:ControlParameter ControlID="ddlWettekst" Name="WetID" Type="Int32" PropertyName="SelectedValue" /><%--<asp:QueryStringParameter QueryStringField="WetID" Name="WetID" Type="Int32" />--%></SelectParameters></asp:EntityDataSource></td><td class="tdSpace"></td><td class="tdWetTekstHeader"><asp:DetailsView ID="DetailsView1" runat="server" CssClass="dtvWetTekst"
                    AutoGenerateRows="False" RowStyle-VerticalAlign="NotSet" GridLines="None"
                    BorderWidth="0px" BorderStyle="None" DataSourceID="edsWetTitel"><Fields><asp:BoundField DataField="Wet_Titel" ShowHeader="false" ReadOnly="True" SortExpression="Wet_Titel"></asp:BoundField></Fields></asp:DetailsView><asp:EntityDataSource runat="server" ID="edsWetTitel" DefaultContainerName="DBBouwgegevensEntities" 
                    ConnectionString="name=DBBouwgegevensEntities" EnableFlattening="False" EntitySetName="tbl_WetTeksten" 
                    Select="it.[WetTekstID], it.[Wet_Titel]" Where="it.[WetTekstID]=@WetTekstID"><WhereParameters><asp:ControlParameter ControlID="trvWetTekst" Name="WetTekstID" PropertyName="SelectedValue" Type="Int32" /></WhereParameters></asp:EntityDataSource></td></tr><tr><td class="tdWetMenuContent"><asp:TreeView ID="trvWetTekst" runat="server" ClientIDMode="Static"
                    ExpandDepth="0" ForeColor="#6A8486" NodeWrap="True" Font-Size="9pt"
                    SelectedNodeStyle-ForeColor="#FF6600" ShowExpandCollapse="true" Width="275"
                    NodeStyle-VerticalPadding="1px" NodeStyle-NodeSpacing="3px" NodeStyle-HorizontalPadding="3px"
                    ParentNodeStyle-HorizontalPadding="3px"></asp:TreeView></td><td class="tdSpace"></td><td class="tdWetTekstContent"><asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"><ContentTemplate><asp:DetailsView ID="DetailsView2" runat="server" Width="100%" AutoGenerateRows="False"
                            DataKeyNames="WetTekstID" CellPadding="4" ForeColor="#333333" GridLines="None" DataSourceID="edsWetDetailsTekst"><AlternatingRowStyle BackColor="White" ForeColor="#284775"></AlternatingRowStyle><CommandRowStyle BackColor="#E2DED6" Font-Bold="True"></CommandRowStyle><EditRowStyle BackColor="#999999" Width="700px"></EditRowStyle><FieldHeaderStyle BackColor="#E9ECF1" Font-Bold="True" Width="150px"></FieldHeaderStyle><Fields><asp:TemplateField HeaderText="WetOmschrijving" SortExpression="WetOmschrijving" ShowHeader="False"><EditItemTemplate><%--<CKEditor:CKEditorControl ID="CKEditor1" BasePath="~/ckeditor/" runat="server" Text='<%# Bind("Wet_Omschrijving") %>' Width="844px" Height="300px"></CKEditor:CKEditorControl>--%><asp:TextBox runat="server" Text='<%# Bind("Wet_Omschrijving") %>' ID="TextBox3" Width="844px" TextMode="MultiLine"></asp:TextBox></EditItemTemplate><InsertItemTemplate><asp:TextBox runat="server" Text='<%# Bind("Wet_Omschrijving") %>' ID="TextBox3" Width="844px" TextMode="MultiLine"></asp:TextBox></InsertItemTemplate><ItemTemplate><asp:Label runat="server" Text='<%# Bind("Wet_Omschrijving") %>' ID="Label3"></asp:Label></ItemTemplate></asp:TemplateField><asp:CommandField ShowInsertButton="True" ShowEditButton="True" ShowDeleteButton="True"></asp:CommandField></Fields><FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White"></FooterStyle><HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" Width="150px"></HeaderStyle><PagerStyle HorizontalAlign="Center" BackColor="#284775" ForeColor="White"></PagerStyle><RowStyle BackColor="#F7F6F3" ForeColor="#333333"></RowStyle></asp:DetailsView><asp:EntityDataSource runat="server" ID="edsWetDetailsTekst" DefaultContainerName="DBBouwgegevensEntities" 
                            ConnectionString="name=DBBouwgegevensEntities" EnableFlattening="False" EnableUpdate="True" 
                            EntitySetName="tbl_WetTeksten" Where="it.[WetTekstID] = @WetTekstID"><WhereParameters><asp:ControlParameter ControlID="trvWetTekst" Name="WetTekstID" PropertyName="SelectedValue" Type="Int32" /></WhereParameters></asp:EntityDataSource></ContentTemplate><Triggers><asp:AsyncPostBackTrigger ControlID="trvWetTekst" /></Triggers></asp:UpdatePanel></td></tr></table></div></asp:Content>

*.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Bouwgegevens.nl.Sitemanager
{
    public partial class WetTekstEdit : System.Web.UI.Page
    {
        //protected void Page_Init(object sender, EventArgs e)
        //{
        //    PopulateMenu();
        //}
        
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!ScriptManager.GetCurrent(this).IsInAsyncPostBack)
            {
                
                trvWetTekst.Nodes.Clear();
PopulateMenu();
            }
            else
            {
                //code when it is an async postback

                trvWetTekst.Nodes.Clear();
                PopulateMenu();
            
            }
        }

        private void PopulateMenu()
        {
            

            List<tbl_WetTeksten> allMenu = new List<tbl_WetTeksten>();

            using (DBBouwgegevensEntities dc = new DBBouwgegevensEntities())
            {
                allMenu = dc.tbl_WetTeksten.ToList();
            }
            // Call function here for bind treeview
            CreateTreeView(allMenu, 0, null);
            
        }

        private void CreateTreeView(List<tbl_WetTeksten> source, int parentID, TreeNode parentNode)
        {
            int wetId = Convert.ToInt32(ddlWettekst.SelectedValue);

            List<tbl_WetTeksten> newSource = source.Where(a => a.ParentID.Equals(parentID) && a.WetID.Equals(wetId)).ToList();

            foreach (var i in newSource)
            {
                TreeNode newnode = new TreeNode("<b>" + i.Wet_Code + "</b>" + " " + i.Wet_Titel, i.WetTekstID.ToString());
                if (parentNode == null)
                {
                    trvWetTekst.Nodes.Add(newnode);
                }
                else
                {
                    parentNode.ChildNodes.Add(newnode);
                }
                CreateTreeView(source, i.WetTekstID, newnode);
            }
        }
    }
}

How do I get the updatemodeworking.

Kind regards Mark