WCF: is there an attribute to make parameters in the OperationContract required?

Question

I use [DataMember(IsRequired=true)] to make the DataContract properties required. There doesn\'t seem to be some IsRequired for the OperationContract parameters

Answer 1

No. Just like any regular method, you'll need to check whether reference type parameters have a value or are null.

Just apply your normal defensive programming patterns, checking reference types before accessing their properties.

Answer 2

Unfortunately it can't be done using default WCF. There exist a few workarounds:

• A custom RequiredParametersBehavior attribute
• Using the Validation Application Block from the Enterprise Library and associate a ruleset to your method

You can however implement a FaultContract and throw a fault when the input parameter is null.