Resume bookmark against workflow service

I'm using WF4 and have a w开发者_JS百科orkflow service in which I have created a custom activity that creates a bookmark to wait for additional user input. When hosting the workflow with a WorkflowApplication I can simply call ResumeBookmark to pick up processing where I left off but I can't seem to figure out how to resume a bookmark when the workflow is being hosted as a Workflow Service.

Any guidance would be really appreciated.

You need to create an activity extension implementing the IWorkflowInstanceExtension interface and use the BeginResumeBookmark()/EndResumeBookmark() functions provided by the WorkflowInstanceProxy. See here for a simple example.