使用WCF服务暂时使用asmx Web服务

Question

I have an application that is an asmx web service written in .NET 2.0 with some business logic and a repository sitting underneath it.

The plan is that this web service will serve as the API for applications that want the data that it saves and retrieves.

Longer term, I know that the web service is likely to be replaced by a WCF service when the .NET 2.0 code base is refactored and becomes a .NET 4 codebase.

In order to reduce the impact on consumers of the API, I am considering whether it is a good idea to drop a WCF service as a facade over the asmx service. This will remain in place while the .NET 2.0 code is refactored. When there is no .NET 2.0 code left, the asmx service will disappear and the WCF service will talk to the business logic without an asmx service in the way.

My questions are

What kind of performance overhead will this cause?

Is there a better solution to this problem?

Answer 1

You'll pay a double serialization / deserialization penalty for the additional service layer. If your messages are small, this won't be as noticeable.

You might want to deploy a WCF version of the same service using BasicHttpBinding. That way you get the best of both worlds:

• The service is being deployed in one place using WCF (and is still available to legacy clients)
• You can expose additional endpoints using different bindings if you want for the newer code.

EDIT: Of course, you could just hook up your new code to the old code using WCF based proxies. As long as you keep things named the same, your later refactor of the service shouldn't be too painful.

Answer 2

I read your question as “can I reference a .Net 2.0 component from a .Net 4 WCF service"

This link confirms

The .NET Framework 4 is backward-compatible with applications that were built with the .NET Framework versions 1.1, 2.0, 3.0, and 3.5. In other words, applications and components built with previous versions of the .NET Framework will work on the .NET Framework 4.