Question

Am getting an error mentioned below when I call my WCF service?How do i get rid of it?

There was an error while trying to serialize parameter http://tempuri.org/:MyWCFSvc.svc
The InnerException message was ‘Type ‘System.String[]’ with data contract name ‘ArrayOfstring:http://schemas.microsoft.com/2003/10/Serialization/Arrays‘
is not expected. Add any types not known statically to the list of known types – for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.’. Please see InnerException for more details.*

I tried using [ServiceKnownType(typeof(string[]))] in my WCF service interface but no luck

Answer 1

A year late, but I had the same issue and here is what you need to do

List<SomeClass> mylist = new List<SomeClass>();

DataContractSerializer dcs = new DataContractSerializer(mylist.GetType());
XmlWriter writer = XmlWriter.Create(sb, XWS);
dcs.WriteObject(writer, query);      
writer.Close();

The problem is when you construct your serializer with the typeof your class, the serialzer does not see it as an arrray, it only sees a single object.

If found it by doing this first:

DataContractSerializer dcs = new DataContractSerializer(SomeClass.GetType());
XmlWriter writer = XmlWriter.Create(sb, XWS);
dcs.WriteObject(writer, query[0]);  // Only get the first record from linq to sql
writer.Close();