问题
I have a custom activity which is a composite of several activities. There are some activities on the composite where I would like users of the custom activity to be able to drop more activities at design time on the Worfkflow surface.
Custom Composite activities don't allow drag-drop actions out-of-the box, but I have tried using a custom designer and overridden OnDragDrop etc. and that did not work either.
Code samples/snippets in any answers would be most helpful...
来源：https://stackoverflow.com/questions/2208190/windows-wf-3-5-how-to-drop-activity-on-custom-composite-activity-in-workflow