How to return a List<object> in WCF

Question

I have my WCF service returning data both in XML and JSON format.

One functios has to return a List, because I don\'t know which class will be used to fill this list

Answer 1

In my case the solution is more simple.

I have a class that I return in all my mehotds, like this:

[DataContract]
public class Result
    {

        [DataMember]
        public string KeyMensaje;
        [DataMember]
        public string ErrorMessage;        
        [DataMember]        
        public object Objeto;

        ...
   }

The problem is due to Objeto object inside this class. This object is used to return variables types and it can't be serialized if is a complex object, for example:

res = new Result(list, "ok", "", "", "", null);  
return res;

In this case object (list) is a list of other custom object, for example List

The solution is add on top Result class the complex types that object can be, like this:

[DataContract]
[KnownType(typeof(List))]
[KnownType(typeof(CustomEmployee))]
public class Result
{
   ...
}