SOA问题：WCF +依赖项注入

Question

We have the following solution layout:

• DataAccess
• Business Logic
• WCF Services
• MVC

We chose to have a WCF service layer, because in the future there will be other applications using the same logic. That's considered to be SOA.

Between the DA, BL and WCF layer I tend to use dependency injection, because I'd like to unit test the Business Logic etc..

But now my question is: should I use dependency injection for the WCF as well? What I mean is, should I pass dependencies through the WCF services from the application (consumer)? Personally I find that weird, because it then no longer seems SOA to me?

Can anyone help me out?

Answer 1

Might be nitpicking, but using services doesn't mean necessarily SOA.

With that out of our way, why would you need to pass dependencies from the application? You can compose your services on the host as shown here .

Answer 2

If you want to unit test business logic you can even declare different end points for them and consume then in your unit testing, it's an alternate of dependency injection. And if you really want to use dependency injection then it is always advisable to do it on service level rather then on client but still there is no harm if you use it from client. If i would given choice then i would have done it in Service class and from client i could get a parameter which will suggest whether your are using it for unit testing or application has made an call to your WCF service.

Answer 3

should I pass dependencies through the WCF services from the application?

I guess the application you mean the consumer of the WCF service right? I believe from the application(MVC) you are talking to the service layer through proxies. You should not inject dependencies to a WCF service from the consumer application and you can't do that.

But you can use dependency injection in WCF to inject data/logging components for better unit testing in the service side itself by creating custom service host factory.

http://prideparrot.com/blog/archive/2012/2/dependency_injection_in_wcf_using_castle_windsor