Question

Will calling close on my WCF service kill all resources or set them up for GC or should I set it to null also?

Answer 1

Firstly, WCF proxies are IDisposable, so you can kind of use using:

using(var proxy = new MyProxy()) { // see below - not quite enough    // use proxy } 

Unfortunately, WCF also has a buggy Dispose() implementation that regularly throws exceptions. However, here’s a really cool trick to get it to work correctly. I also blogged about this myself, but I think the first link is a lot better.

So: use IDisposable and using, but use it with caution (in this case).

Setting a field usually makes no difference. There are a few edge-cases (such as variables captured by multiple delegates, static fields, long-life objects, etc), but in general leave it alone. In particular, do not do this, as this can theoretically extend the life:

if(field != null) field = null; // BAD