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c#wcfpropertiesdatacontractserializer
Andrey
Andrey

Reputation: 21285

WCF chokes on properties with no "set ". Any workaround?

I have some class that I'm passing as a result of a service method, and that class has a get-only property:

[DataContract]
public class ErrorBase
{
  [DataMember]
  public virtual string Message { get { return ""; } }
}

I'm getting an exception on service side:

System.Runtime.Serialization.InvalidDataContractException: No set method for property 'Message' in type 'MyNamespace.ErrorBase'.

I have to have this property as only getter, I can't allow users to assign it a value. Any workaround I could use? Or am I missing some additional attribute?

Upvotes: 103

Views: 26348

Answers (9)

Aaron Thomas
Aaron Thomas

Reputation: 5281

If your serializer is of type DataContractJsonSerializer (or any DataContractSerializer) you can also use DataContractSerializerSettings in the constructor, with the SerializeReadOnlyTypes property set to true.

Upvotes: 1

Rob Lambert
Rob Lambert

Reputation: 71

If you only have a getter, why do you need to serialize the property at all. It seems like you could remove the DataMember attribute for the read-only property, and the serializer would just ignore the property.

Upvotes: 7

Gilad
Gilad

Reputation: 21

If it's a viable option, then instead of having ErrorBase as the base class, define it as follows:

    public interface IError
    {
        string Message
        {
            [OperationContract]
            get;

            // leave unattributed
            set;
        }
    }

Now, even though a setter exists, it's inaccessible to the client via WCF channel, so it's as if it were private.

Upvotes: 2

Rikin Patel
Rikin Patel

Reputation: 9383

[DataMember(Name = "PropertyName")]
public string PropertyName
{
    get
    {
        return "";
    }
    private set
    { }
}

Upvotes: 12

Thomas Lundström
Thomas Lundström

Reputation: 1599

I had this problem with ASP.NET MVC and me wanting to use DataContractSerializer in order to be able to control the names on the items in the JSON output. Eventually I switched serializer to JSON.NET, which supports properties without setters (which DataContractSerializer doesn't) and property name control (which the built-in JSON serializer in ASP.NET MVC doesn't) via [JsonProperty(PropertyName = "myName")].

Upvotes: 2

Jojo Sardez
Jojo Sardez

Reputation: 8568

Properties with DataMember attribute always requires set. You should re write simmilar object on the client application since DataContract members can always be assigned values.

Upvotes: 2

marc_s
marc_s

Reputation: 754458

Couldn't you just have a "do-nothing" setter??

[DataContract]
public class ErrorBase
{
  [DataMember]
  public virtual string Message 
  {
      get { return ""; } 
      set { }
  }
}

Or does the DataContract serializer barf at that, too??

Upvotes: 5

rh.
rh.

Reputation: 1721

Give Message a public getter but protected setter, so that only subclasses (and the DataContractSerializer, because it cheats :) may modify the value.

Upvotes: 112

Russell
Russell

Reputation: 17719

Even if you dont need to update the value, the setter is used by the WCFSerializer to deserialize the object (and re-set the value).

This SO is what you are after: WCF DataContracts

Upvotes: 13

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