GraphLayout throws ArgumentNullException in design mode

Jun 26, 2012 at 4:13 PM

I'm unable to get a GraphLayout to render in design mode.  I get an ArgumentNull exception with the stack trace running through MS.Internal.Designer.DesignerPane.LoadDesignerView and ultimately failing at System.RuntimeType.MakeGenericType(Type[]).

I would appreciate any suggestions as to how to solve this one.  Its not critical but an inconvenience when working with the designer.

Here is my xaml.  When commented out, the designer loads without error.

<local:MyGraphLayout 
Graph="{Binding Path=MyGraph, Mode=OneTime}" LayoutAlgorithmType="ISOM" 
LayoutMode="Simple" 
OverlapRemovalAlgorithmType="FSA" OverlapRemovalContraint="Automatic"/>

The graph layout class is pretty simple as well:

public class MyGraphLayout : GraphLayout<MyVertex, MyEdge, MyGraph>
{
   public MyGraphLayout()
   {
      //if(DesignerProperties.GetIsInDesignMode(this)) 
      { 
            /* sample data */ 
      }
   }
}

Where:

MyEdge : TypedEdge<MyVertex>
MyGraph : BidirectionalGraph<MyVertex, MyEdge>