WCF Sorting and filtring

Answer 1

Sorting and filtering and WCF have nothing to do with eachother. WCF is about communication between processes. What you communicate about isn't interesting from the WCF point of view.

So you have to implement sorting and filtering yourself (as in most cases). There is nothing wrong with providing a parameter that specifies your sorting criteria.

As for lazy loading, I suppose you would want to do something like this?

• get object a from web service and load all primitive properties
• on the client call a.ListOfObjects
• ListOfObjects for instance a is automagically loaded from the web service

This is also something you have to do yourself. You could take a look at ADO.NET Data Services for this. No lazy-loading but a similar pattern.