Question

I have been looking into the Castle project and specifically Windsor. I have been so impressed with what is possible with this technology and the benefits of having a such a loosely coupled system are definitely apparent. The only thing I am unsure of is if using this method has any downsides, specifically in asp.net? for example performance hits, etc.

I am trying to make the benefits of this approach visible to my fellow developers here and am being hit with the following comebacks:

1. That is using reflection and each time that an object is called from the container, reflection must used so performance will be terrible. (Is this the case? does it use reflection on every call?)

2. If I am relying on Interfaces; how do I deal with objects that have extra methods and properties which have been tacked onto the class? (through inheritance)

Answer 1

To answer your questions:

1. That is using reflection and each time that an object is called from the container, reflection must used so performance will be terrible. (Is this the case? does it use reflection on every call?)

• No, it does not. Most of the time it uses little reflection when you register the component. It may also use reflection while generating proxy type, first time you request a component from the container.

2. If I am relying on Interfaces; how do I deal with objects that have extra methods and properties which have been tacked onto the class? (through inheritance)

• It’s all a matter of design. You don’t want to have each and every object created by the container. You use it primarily for service dependencies. In this case, you don’t care about what type is actually hiding behind the interface (that’s the whole point of it, isn’t it?).

You also can have class components, but they have limitations, and you must be aware of those (for example you can’t intercept calls to non-virtual methods). I have found Windsor to be the most mature, and best suited to my style of development container of all.

Other than that, Performance, I haven’t heard of a project that had to discard dependency container because of unacceptable performance. Windsor is really smart about it, and it caches the results of lengthy operations so that you don’t have to pay the price twice. You may find charts on the Internet, comparing speed of many IoC containers. Two things to note about those: All containers are really fast. Don’t think that the fact that other containers are faster on these charts than Windsor, means that they are better. Windsor does a lot of stuff for you that other containers don’t.