Issue in exposing custom generic entities in WCF proxy code.

Question

Hi All

 I have following custom generic entity
 
    [Serializable]
    [CollectionDataContract(Name = "{0}EntityCollection", Namespace = "http://himanshu.org/Entities")]
    [KnownType(typeof(EmployeeBE))]
    [KnownType(typeof(EmployeeLookupBE))]
    public class EntityCollection<T> : CollectionBase
    {
        .....
    }
 
 I use it to create collections of types "EmployeeBE" and "EmployeeLookupBE".
 
 When I generate proxy for my service it creates two separate types for "EmployeeBE" and "EmployeeLookupBE"
 as follows:

    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="EmployeeLookupBEEntityCollection", Namespace="http://himanshu.org/Entities", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class EmployeeLookupBEEntityCollection : System.Collections.Generic.List<object> 
    {
          ......
    }
 
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="EmployeepBEEntityCollection", Namespace="http://himanshu.org/Entities", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class EmployeeBEEntityCollection : System.Collections.Generic.List<object>
   {
      ......
   }
 
 Issue:
 
 I am expecting the type argument of Generic List for these classes to be "EmployeeLookupBE" and "EmployeeBE" respectively, making the code look like below:
 
 [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="EmployeeLookupBEEntityCollection", Namespace="http://himanshu.org/Entities", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class EmployeeLookupBEEntityCollection : System.Collections.Generic.List<EmployeeLookupBE>
   {
      .......
   }
 
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="EmployeeLookupBEEntityCollection", Namespace="http://himanshu.org/Entities", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class EmployeeBEEntityCollection : System.Collections.Generic.List<EmployeeBE>
   {
     .......
   }
 
 Not sure why it is not taking the exact types, it should take.

Answer 1

Hi,

Can you post a bit more code as I didn't reproduce your issue.

This is what I defined:
 // [DataContract]
    public class Parent
    { 
    public string test = "this is parent test";
    }
   
    //[DataContract]
    public class Child : Parent
    {
        public string test1 = "this is child test";
    }
  
    [CollectionDataContract]
    [KnownType(typeof(Parent))]
    [KnownType(typeof(Child))]
    public class CustomCollection<T> : CollectionBase
    {
          public CustomCollection()
        : base()
        {
         }
    }
The generated proxy will be:

 [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="CustomCollectionOfParentRkK6MCnv", Namespace="http://schemas.datacontract.org/2004/07/WcfService4", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class CustomCollectionOfParentRkK6MCnv : System.Collections.Generic.List<object> {
    }
   
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.DataContractAttribute(Name="Parent", Namespace="http://schemas.datacontract.org/2004/07/WcfService4")]
    [System.SerializableAttribute()]
    [System.Runtime.Serialization.KnownTypeAttribute(typeof(Client.ServiceReference1.Child))]
    public partial class Parent : object, System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged {
        
           }
   
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.DataContractAttribute(Name="Child", Namespace="http://schemas.datacontract.org/2004/07/WcfService4")]
    [System.SerializableAttribute()]
    public partial class Child : Client.ServiceReference1.Parent {
        
             }

Thanks
Binze

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Answer 2

Hi

You have reproduced the problem partially. The first class in your proxy code which is as below:

[System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
    [System.Runtime.Serialization.CollectionDataContractAttribute(Name="CustomCollectionOfParentRkK6MCnv", Namespace="http://schemas.datacontract.org/2004/07/WcfService4", ItemName="anyType")]
    [System.SerializableAttribute()]
    public class CustomCollectionOfParentRkK6MCnv : System.Collections.Generic.List<object> {
    }

should have the type argument for the generic list to be 'Parent' and not 'object'.

This is the issue I am trying understand.

Thanks
Himanshu.