When I create a custom control, I need to edit some value with Object data type (like Tag Property) on Design Time for my class (you can see TreeNodeItem in my MultiColumnTree article). Previously, a was able to create a MultilineTextEditor inherited from UITypeEditor to edit a Multiline string data, but I am unable to create an Object editor. When I used default editor (no editor specified), I was unable to edit its value (the editor is readonly, and the default value for this property is Nothing). Is there a way to create an editor for Object data type? or, I must change its default value?