Azure Service Bus Queue - Serialization with BrokeredMessage

Question

Trying to submit a queue message with an object in the message body but receiving exception on the following line with BrokeredMessage

QueueClient queueClient = QueueClient.CreateFromConnectionString(_connectionString, _queuePathName);
var data = new ABSurvey
                {
                    name = "somename",
                    version = 1,
                    language = "eng",
                    SelfSurvey = new Survey()
                    {
                        SurveyItems = new List<ISurveyItem>() { new SurveyItem(){IsSelected = true, ItemId = 1}},
                        SurveyPerception = Constants.Perception.Self
                    },
                    SelfConcept = new Survey()
                    {
                        SurveyItems = new List<ISurveyItem>() { new SurveyItem(){IsSelected = true, ItemId = 1}},
                        SurveyPerception = Constants.Perception.SelfConcept
                    }
                };
                BrokeredMessage message = new BrokeredMessage(data);
                queueClient.Send(message);

Exception Message - Type '.Survey' with data contract name 'Survey:http://schemas.datacontract.org/2004/07/namespace' is not expected. Consider using a DataContractResolver 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 DataContractSerializer.

These are the models I have -

    [DataContract]
public class ABSurvey
{
    [DataMember] public string name;
    [DataMember] public int version;
    [DataMember] public string language;
    [DataMember] public ISurvey SelfSurvey;
    [DataMember] public ISurvey SelfConcept;
}

[DataContract]
public class SurveyItem : ISurveyItem
{
    [DataMember]
    public int ItemId { get; set; }
    [DataMember]
    public bool IsSelected { get; set; }
    public SurveyItem()
    {
        ItemId = -1;
        IsSelected = false;
    }
}

[DataContract]
public class Survey : ISurvey
{
     [DataMember]
    public IList<ISurveyItem> SurveyItems { get; set; }
     [DataMember]
    public Constants.Perception SurveyPerception { get; set; }
    public Survey()
    {
        SurveyItems = new List<ISurveyItem>();
    }
}

public interface ISurvey
{
    [DataMember]
    IList<ISurveyItem> SurveyItems { get; set; }
    [DataMember]
    Constants.Perception SurveyPerception { get; set; }
}
public interface ISurveyItem
{
    [DataMember]
    int ItemId { get; set; }
    [DataMember]
    bool IsSelected { get; set; }
}

Please help locate the issues.

b2zw2a b2zw2a · Accepted Answer · 2014-11-07T11:01:24

You are missing [KnownType] attributes on your data contract and that is why your message can't be serialized. Detailed explanation can be found hehe.

Simply add [KnownType] attributes to tell serializer which concrete implementation can be used:

[KnownType(typeof(Survey))]
[DataContract]  
public class ABSurvey
{
    [DataMember]
    public string name;
    [DataMember]
    public int version;
    [DataMember]
    public string language;
    [DataMember]
    public ISurvey SelfSurvey;
    [DataMember]
    public ISurvey SelfConcept;
}

[KnownType(typeof(SurveyItem))]
[DataContract]
public class Survey : ISurvey
{
    [DataMember]
    public IList<ISurveyItem> SurveyItems { get; set; }

    public Survey()
    {
        SurveyItems = new List<ISurveyItem>();
    }
}

Azure Service Bus Queue - Serialization with BrokeredMessage

1 Answers