Passing a dynamic data member of an array of types in WCF

Before you start regretting the length of this post ...

Does anyone know why I can't pass an array of a class as a dynamic property through WCF?

I have a ServiceOperationResponse class that is used to pass messages around my solution as shown below.

The message details datamember is a dynamic type that allows you to easily pass any object. This works in almost any circumstance, since I can set the ServiceKnownType for each of the WCF server interfaces.

However, if I try to pass a ServiceOperationResponse object through WCF when the MessageDetails property is an array itself or a list of type ServiceOperationResponse, I get the following error:

The InnerException message was "Error at line 1 position 576. The element" http://schemas.datacontract.org/2004/07/Library:MessageDetails "contains data from the type that matches the name" http://schemas.datacontract.org / 2004/07 / Library: ArrayOfServiceOperationResponse. Deserializer does not know any type that matches this name.

This happens when I set the ServiceKnownType to any of the following: ServiceOperationResponse [], List.

Other types of lists or arrays can be passed without problem, also if I create another property of type ServiceOperationResponse [], that is, an array of responses, basically ServiceOperationResponse and populate it, and then all data is deserialized properly. However, I would prefer it if there was no need to add this property for just one particular case at all.

/// <summary>
/// Class used to pass details between services
/// </summary>
[DataContract]
public class ServiceOperationResponse
{
    /// <summary>
    /// the originating hostname or keyname
    /// </summary>
    [DataMember]
    public string HostName { get; set; }

    /// <summary>
    /// the operation name
    /// </summary>        
    public string OperationName { get; set; }

    /// <summary>
    /// the particular message details
    /// </summary>
    [DataMember]
    public dynamic MessageDetails { get; set; }
}

      

        
        
        
      

    

the below is a sample code that will crash if I try to stream back from WCF to a client

var responseList = new List<ServiceOperationResponse>();
        for (int i = 0; i < 3; i++)
        {
            var responseElement = new ServiceOperationResponse()
            {
                HostName = Environment.MachineName,
                MessageDetails = "this is a test"
            };
          responseList.Add(responseElement);
        }

        var response = new ServiceOperationResponse()
        {
            HostName = Environment.MachineName,
            OperationName = "Get a list of service responses",
            MessageDetails = responseList
        };