Question

I have a base usercontrol in my ASP.Net app, There are HTML markup within this usercontrol that are set to runat=”server” and id’s. The problem I am having is when the usercontrol is loaded, the HTML markup is being returned as null

ASP.Net C# code:

public partial class webonlinecustombase : System.Web.UI.UserControl
{
    public Event Event { get; set; }
    public OnlineSystemPageCustom custompage { get; set; }
    public OnlineSystemPageCustom.OnlineSystemPageHdr.OnlineSystemPageModule custommodule { get; set; }

    public void Page_Load(object sender, EventArgs e)
    {
        string typeName = custommodule.ModuleInternetFile;
        inpagelink.HRef = "#" + custommodule.ModuleName.Replace(" ", "").Replace("/", "");
        modtitle.InnerText = custommodule.ModuleName;
        Type child = Type.GetType(typeName);
        UserControl ctl = Activator.CreateInstance(child) as UserControl;
        if (ctl != null)
        {
            this.modsection.Controls.Add(ctl);
        }
    }
}

Here is the HTML Markup:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="webonlinecustombase.ascx.cs" Inherits="IPAMIntranet.IPAM_Controls.webtemplatecontrols.webonlinecustombase" %>
<a id="inpagelink" runat="server"></a>
<span id="modtitle" runat="server" style="width:100%;text-align:left">Scientific Overview</span>
<div id="modsection" runat="server" style="width:100%;">
</div>
<p><a href="#top" class="bodylink">Back to Top</a></p>

Why is the inpagelink and modtitle being returned as null?

Answer 1

I have seen this happen in web applications (not web sites) when changes are made to the source (especially setting runat=server on items that were not previously runat=server), but you don’t switch to the designer view.

The way that I resolve this issue is to switch to design view and dirty a property in one of the fields. This usually causes VS to update the designer code-behind file.

You can double-check this file to ensure the controls have been added. If you check it prior to doing this, you should see that they are missing.