Unknown build error in BusyIndicator using Extended WPF Toolkit

Mar 1, 2011 at 2:35 AM
Edited Mar 1, 2011 at 2:17 PM

hello guys,

I am trying to add a BusyIndicator to my project using the Extended WPF Toolkit, i write out:




and this:


<extToolkit:BusyIndicator IsBusy="True" />


and i get an error:


Unknown build error, 'Cannot resolve dependency to assembly 'WPFToolkit, Version=3.5.40128.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 
because it has not been preloaded. When using the ReflectionOnly APIs, dependent assemblies must be pre-loaded
or loaded on demand through the ReflectionOnlyAssemblyResolve event.

I can see it just fine in the designer but this error occurs only when i try to compile..

I already had success with the Extended WPF Toolkit when using the NumericUpDown control


I am using Microsoft Windows 7, I have Microsoft .Net Framework 4.0 installed.

In order to create my project i use Microsoft Visual Studio 2010, compiling to Microsoft .Net Framework 3.5 Client Profile


what should i do?

thanks in advanced,


Mar 1, 2011 at 2:12 PM

Since you are using the .NET 3.5 version of the Extended WPF Toolkit, you must also have a reference to the normal WPF Toolkit because there is a dependency on the VisualStateManager.  If you read the Downloads page there is a note at the bottom that explains this.  You can get the WPF Toolkit here here.  Let me know if you have anymore problems and thanks for using the Extended WPF Toolkit.

Mar 1, 2011 at 2:31 PM
Edited Mar 1, 2011 at 2:41 PM

Thanks for the info, i didn't see that note Oo

Mar 1, 2011 at 2:36 PM

No, you can keep your project targeting the .NET 3.5 framework, but you must add a reference to Microsoft's WPF Toolkit also.  The .NET 3.5 version of my Extended WPF Toolkit has a dependency on Microsoft's WPF Toolkit.  Therefore you must also reference to it.  If you decided to target the .NET 4 framework you would not need this dependecy and only the WPFToolkit.Extended.dll would be required.  I hope this clears things up.

Referneces need per framework:

  1. .NET 3.5
    1. WPFToolkit.Extended.dll
    2. WPFToolkit.dll (Microsoft's)
  2. .NET 4.0
    1. WPFToolkit.Extended.dll


Mar 1, 2011 at 2:56 PM

Got it :)

Thanks again