DiagramNodeTool cursor not displaying when using DynamicResources

Using the CustomNodeType sample, if we use DynamicResources for constructing the CursorVisual, the cursor doesn't display.

Take this example:

<ms:DiagramNodeTool Margin="10" Builder="{ms:BuilderType local:SendMessageNodeBuilder}" ToolTip="Send Message">
   <ms:DiagramNodeTool.CursorVisual>
       <!-- ## DynamicResource Used Here ## -->
       <Path Style="{DynamicResource ToolboxCursorVisual}" Data="M 0 0 L 0.8 0 L 1 0.5 L 0.8 1 L 0 1 L 0.2 0.5 Z" Stretch="Fill" />
   </ms:DiagramNodeTool.CursorVisual>
   <Path Style="{StaticResource ToolboxItem}" Data="M 0 0 L 0.8 0 L 1 0.5 L 0.8 1 L 0 1 L 0.2 0.5 Z" Stretch="Fill" />
</ms:DiagramNodeTool>

Notice that we changed the Style property of the CursorVisual Path to use a DynamicResource. When doing this, nothing renders when we drag the shape from the toolbox. It's worth noting that using a DynamicResource for the DiagramNodeTool itself works as expected.

In this contrived example, it's simple to just use a StaticResource. In our application, we have global style definitions in a separate assembly, so we need to be able to use DynamicResources.

Is there another way to approach this, or is this something that can be resolved?

Hello

The only way I could get this to work is to include a resource dictionary containing the ToolBoxCursorVisual style as a merged dictionary on the Path like this:

<Path Style="{DynamicResource ToolboxCursorVisual}" Data="M 0 0 L 0.8 0 L 1 0.5 L 0.8 1 L 0 1 L 0.2 0.5 Z" Stretch="Fill">
    <Path.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <myNameSpace:myDictionary />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Path.Resources>
</Path>

An ugly solution, but at least it worked.

Jason Fauchelle

That's an interesting workaround, but is a less-than-desirable solution. Do you have any insight as to why the CursorVisual is not playing nicely with DynamicResource references?

Hello

I think it has something to do with the CursorVisual not being directly in the visual tree in xaml. It is simply held by a property which we then use to add to the adorner layer at runtime. This is the only difference I can find between the CursorVisual and other objects which just work with dynamic resources. I have not found a way to resolve this which is a shame because the solution I mentioned is far from ideal. If you happen to find information about making this more convenient we'd love to hear about it.

Jason Fauchelle