Use base class as parameter for WCF Service

Question

I have a multi-project solution. One Project is providing a DLL containing multiple classes.

One of those classes is WorkerTemplate. Two other classes inher

Answer 1

The error message tells you what to do:

The InnerException message was 'Type 'DV_BII30.ExecSQLWorker' with data contract name 'ExecSQLWorker:http://schemas.datacontract.org/2004/07/DV_BII30' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or 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 the serializer.'. Please see InnerException for more details. ---> System.Runtime.Serialization.SerializationException: Type 'DV_BII30.ExecSQLWorker' with data contract name 'ExecSQLWorker:http://schemas.datacontract.org/2004/07/DV_BII30' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or 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 the serializer.

You have a couple of possibilities to solve this issue.

1. Add to your WorkerTemplate class the KnownTypeAttribute

   [DataContract]
   [KnownType(typeof(ExecSQLWorker))]
   [KnownType(typeof(CopyWorker))]
   public class WorkerTemplate
   {
       //Properties and stuff
   }
   

2. If you can change the IPQWService interface, take a look here

3. You can use a DataContractResolver

   public class SharedTypeResolver : DataContractResolver
   {
       public override bool TryResolveType(Type dataContractType, Type declaredType, DataContractResolver knownTypeResolver, out XmlDictionaryString typeName, out XmlDictionaryString typeNamespace)
       {
           if (!knownTypeResolver.TryResolveType(dataContractType, declaredType, null, out typeName, out typeNamespace))
           {
               XmlDictionary dictionary = new XmlDictionary();
               typeName = dictionary.Add(dataContractType.FullName);
               typeNamespace = dictionary.Add(dataContractType.Assembly.FullName);
           }
       }
   
       public override Type ResolveName(string typeName, string typeNamespace, Type declaredType, DataContractResolver knownTypeResolver)
       {
           return knownTypeResolver.ResolveName(typeName, typeNamespace, declaredType, null) ?? Type.GetType(typeName + ", " + typeNamespace);
       }
   }
   

   The Resolver accepts every type you use in your service. But you have to add the resolver to your Client endpoint and server endpoint. Like this:

   Host = new ServiceHost(typeof(MyService));
   
   ContractDescription cd = Host.Description.Endpoints[0].Contract;
   foreach (var operation in cd.Operations)
   {
       operation.Behaviors.Find<DataContractSerializerOperationBehavior>()
               .DataContractResolver = new SharedTypeResolver();
   }