Hi,

I've had a good search around but can't seem to find the issue with this. I've made a little breadcrumb system for the top of our pages which is generated from a collection. Until yesterday it was working fine but suddenly (and to my knowledge without a change in the code) its stopped rendering in the Design Time view of visual studio with the error "Error Creating Control". Here's my code (some omitted for brevity). Can anyone see what?s wrong?

Thanks.

Tim

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using Common.Geographics;
using System.Collections;
using Data.Constants;
 
namespace NavigationControls
{
      /// <summary>
      /// Generates a breadcrumb system of the current location
      /// </summary>
      [
      DefaultProperty("Text"),
      ToolboxData("<{0}:AreaBreadCrumbs runat=server></{0}:AreaBreadCrumbs>"),
      Designer("NavigationControls.wcAreaBreadCrumbsDesigner, GeneralControls")
      ]
      public class AreaBreadCrumbs : System.Web.UI.WebControls.WebControl
      {
            /// <summary>
            /// strRender is set to display links Design View.
            /// </summary>
            private string strRender = "<a>Home</a> > <a>Level 1</a> > <a>Level 2</a> > <a>Level 3</a>";
            private string strNoRender = "Not Visible at Runtime with Current Settings";
 
            [
            Bindable(true),
            Category("Custom"),
            DefaultValue(""),
            Description("Set the Design View Render HTML String")
            ]
            public string RenderHTML
            {
                  get
                  {
                        return strRender;
                  }
 
                  set
                  {
                        strRender = value;
                  }
            }
 
            [
            Bindable(true),
            Category("Custom"),
            DefaultValue(""),
            Description("Set the Design View NoRender HTML String")
            ]
            public string NoRenderHTML
            {
                  get
                  {
                        return strNoRender;
                  }
 
                  set
                  {
                        strNoRender = value;
                  }
            }
 
 
            protected override void CreateChildControls()
            {
                  //Code ommitted              
            }
      }
 
      /// <summary>
      /// Summary description for wcCountryCodeControlDesigner.
      /// </summary>
      public class wcAreaBreadCrumbsDesigner : System.Web.UI.Design.ControlDesigner
      {
            public override string GetDesignTimeHtml()
            {
                  //cast the underlying Component to a AreaBreadCrumbs
                  //so that we have access to the design time Property - RenderHTML
                  AreaBreadCrumbs bc = (AreaBreadCrumbs)Component;
                  return bc.RenderHTML;
            }
            protected override string GetEmptyDesignTimeHtml()
            {
                  //cast the underlying Component to a CountryCodeDropDownList
                  //so that we have access to the design time Property - NoRenderHTML
                  AreaBreadCrumbs bc = (AreaBreadCrumbs) Component;
                  return CreatePlaceHolderDesignTimeHtml(bc.NoRenderHTML);
            }
      }
}

1. Start by pointing to the (!) icon. It should give a tooltip that contains the error message (from the Exception thrown). That should help.

2. Run the page. Do you get an exception? If so, it may be the same problem and give you a stack trace to assist you. In addition, if you have a debugger (you SHOULD have one), you can use it to track down the cause.

---

--- Peter Blum
Creator of Professional Validation And More Suite, Peter's Date Package, and Peter's Polling Package
www.PeterBlum.com

Hi Peter,

Thanks for your response however I perhaps wasn't clear, the issue is in Visual Studio's Design time view, the control loads without a problem and there is no exception thrown.

I don't beleive I can debug it if its not actually running but please feel free to correct me if I'm wrong.

Tim

Its quite possible to debug design mode. In fact, I do it regularly.

1. Open VS.NET and open your project.
2. Setup breakpoints in the code related to design mode if you have a clue where to debug
3. Enable "Break into the debugger" for exceptions. Debug menu; Exceptions; Common Runtime Language Exceptions (all of them)
4. Open a second instance of VS.NET. Don't open a project yet.
5. Return to the first VS.NET. Choose Debug; Processes.
6. Attach to "devenv.exe". This is the other instance of VS.NET. Close the Processes window.
7. Return to the second VS.NET and open your project.
8. Open a web form with the problem in design mode.
You will hit the breakpoint or stop on an exception.

---

--- Peter Blum
Creator of Professional Validation And More Suite, Peter's Date Package, and Peter's Polling Package
www.PeterBlum.com