Solution: Add Service Reference does not always work properly in WF4 scenarios
Now, the title is a bit cryptic, so let me elaborate; earlier this week, I noticed that when I tried to add a service reference to a WCF Workflow service in the same ASP.NET Web Application, I didn’t get the expected result; custom activities for the service operations in the toolbox (when designing another WF Service).
Investigating further, I created a Workflow Console Application and checked if I got the same behavior; no – it worked perfectly. Same happened when I tried it with WCF Workflow Service Application / Declarative Service Library (Visual Studio templates).
Putting one and one together, I guessed that it had something about the definition of the project template. Visual Studio projects has a concept of ProjectTypeGuids that enables/disables specific features for a project once added. A couple of years ago, I noticed that I had to add a specific GUID in order to wire in the “F5 experience” when debugging WCF libraries.
When comparing the GUIDs set in one of the working projects with the ones in the ASP.NET Web Application, I noticed the following (magic number):
I retrofitted the GUID in the Web Application, added a service reference to a workflow service;
Building the project and presto! — custom activities for the service operations in the toolbox.
Now, this isn’t just a problem that can happen when using Workflow Services, it can also happen (as I’ve already mentioned) to WCF projects, test project et cetera too. My suggestion to Microsoft is that they in the future add an section somewhere in the Options pages where it is possible to turn on/off features like this one, so developers don’t need to turn autistic and start remembering a large set of project type GUIDs :-) (Oh, no offense to devs (or others) that actually are autistic).
Thanks @mwinkle for putting me in touch with the Add Service Reference guys, even though I found the workaround first :-)