Question

I’m trying to rehost the designer, but every time I slap a workflow into the designer:

_workflowDesigner = new WorkflowDesigner();
// added to UI here
Properties.Content = _workflowDesigner.PropertyInspectorView;
_workflowDesigner.Load(myWorkflowInstance);

where myWorkflowInstance is a workflow defined in a referenced assembly. I have done the magic Register to get the default activity metadata registered:

new DesignerMetadata().Register();

and I’ve registered all my custom NativeActivities:

public static void Register(IEnumerable<Type> activityTypes)
{            
    // activityTypes are all my custom NativeActivities
    // and all workflows (root of System.Activities.Activity)
    var builder = new AttributeTableBuilder();
    var attrGroups =
        from x in activityTypes
        from y in x.GetCustomAttributes(true).OfType<Attribute>()
        group y by x into g 
        select g;

    foreach (var typeGroup in attrGroups)
        builder.AddCustomAttributes(typeGroup.Key, typeGroup.ToArray());
    MetadataStore.AddAttributeTable(builder.CreateTable());
}

yet, when I load an activity in the designer this is what I get:

What am I missing here?

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I’m thinking it has something to do with the fact that these workflows are compiled and only exist within the Implementation property of an Activity…

Answer 1

Is your workflow instance wrapped in an ActivityBuilder?

Update:
Investigating a little further here I found one possible solution using the WorkflowInspectionServices.

var activities = WorkflowInspectionServices.GetActivities(new DemoWorkflow());
designer.Load(activities.First());