Question

I have a WCF service which serves as a remote file/folder browser. We also plan on having a Windows Service that will serve as 3 functions.

1. Windows Service will start the WCF service so it can do its job (part of the same project)
2. Windows Service will Upload some data to an SQL server every few minutes based on a timer + many other methods like this
3. WCF will Receive a request to run a method as requested by an asp.net client via WCF and then ask the windows service to run a method and return a result to WCF and pass back the result to ASP.net.

Item 3 is the problem. How is a windows service supposed to talk to a WCF Service (and Vice-Versa) service that both run on the same machine and are essentially the same application running as one. is it over WCF again?

Possibly i am going about this all wrong. Hopefully someone may be able to help

thanks
Damo

Answer 1

WCF Services may be hosted within Windows Services. See http://msdn.microsoft.com/en-us/library/ms750530.aspx. The specific example they give is for a console application, but the same concept applies.

When self hosting, you can eiter specifiy a type that will be instantiated when a client connects to the service , or you pass the instance that your clients will use when they hit the service. In either case, you can instantiate the same class or access the instance passed to ServiceHost to call methods on the service, though they would not go through the WCF pipeline. The WCF Service class can get a reference to the Windows Service class and access methods on that to allow for callbacks to occur without another trip through the WCF stack.

Alternatively, if you do not wish to self-host or your application uses WCF specific calls in the service, you can create a wcf client in the service in the same way as you would on a desktop application. Simply add a service reference as normal and use callbacks to hop back to the Windows Service code.