Not all communications will be local communications. Windows Workflow provides web service interoperability as an additional feature. WF allows us to expose a workflow as a web service, and consume a web service from a workflow.
In this section, we'll build a workflow to deploy as a web service. Our starting project will be a sequential workflow library. A library is ideally suited for hosting in an ASP.NET web application. We can rename Workflow1.cs
in the new project to HelloWorldWorkflow.
Just like local communication services, web services require a contract that defines the members of a web service. The contract is an interface, but without all the data exchange attributes we've used in previous communication interfaces. The interface for our HelloWorld
workflow is shown below:
interface IHelloWorldService { string GetHelloWorldMessage(string name); }