WPF Application project with a WF Activity in it generates errors on Generics types

I have a WPF Application with a subfolder that contains a WF Activity and a CodeActivity.

At compile-time on the Workflow that uses the CodeActivity, I get this error:

The tag 'Dictionary' does not exist in XML namespace 'clr-namespace:System.Collections.Generic;assembly=mscorlib'. Line 4 Position 8.

The portion of code that reports the error is generated by the Visual studio built-in Activity designer. E.g. this:

<sap:WorkflowViewStateService.ViewState>
  <scg3:Dictionary x:TypeArguments="x:String, x:Object">
    <x:Boolean x:Key="IsExpanded">False</x:Boolean>
    <av:Point x:Key="ShapeLocation">270,2.5</av:Point>
    <av:Size x:Key="ShapeSize">60,75</av:Size>
    <av:PointC开发者_如何学运维ollection x:Key="ConnectorLocation">300,77.5 300,107.5 300,112.5</av:PointCollection>
  </scg3:Dictionary>

I'd like to know if I am trying to something that is not allowed or if I am missing something.

Thanks in advance,

Gianluca

---

I had a similar problem today; at least the same error message. The problem for me was that the build action of the .xaml file was set to Page. It needs to be set to XamlAppDef. If you open a vanilla Workflow console application project, you'll see that. You can't change it in the drop down, you need to edit the .csproj file (again, compare to vanilla VS workflow console project).