How to find out if class has DataContract attribute?

Question

I'm writing a serialization function that needs to determine whether class has DataContract attribute. Basically function will use DataContractSerializer if class has DataContract attribute, otherwise it will use XmlSerializer.

Thanks for your help!

Spout

Answer 1

The simplest way to test for DataContractAttribute is probably:

bool f = Attribute.IsDefined(typeof(T), typeof(DataContractAttribute));

That said, now that DC supports POCO serialization, it is not complete. A more complete test for DC serializability would be:

bool f = true;
try {
    new DataContractSerializer(typeof(T));
}
catch (DataContractException) {
    f = false;
}

Second

Set this answer as accepted because I don't have to get all attributes. – Spout

I could only get the second example to compile using an InvalidDataContractException. – Larissa

Answer 2

    bool hasDataContractAttribute = typeof(YourType)
         .GetCustomAttributes(typeof(DataContractAttribute), true).Any();

Flagrant

Nice answer. In LINQ, it's generally better to use Any() than Count() > 0 for both performance and readability, but in this case it's an academic distinction. – Rota

If you have an object of the class, better to replace typeof(YourType) with this.GetType() – Zygoma

Answer 3

Try something like:

object o = this.GetType().GetCustomAttributes(true).ToList().FirstOrDefault(e => e is DataContractAttribute);

bool hasDataContractAttribute = (o != null);

Circle

Answer 4

I found that in addition to checking for DataContractAttribute, you should also allow for System.ServiceModel.MessageContractAttribute and System.SerializableAttribute.

bool canDataContractSerialize = (from x in value.GetType().GetCustomAttributes(true)
                                 where x is System.Runtime.Serialization.DataContractAttribute
                                 | x is System.SerializableAttribute
                                 | x is System.ServiceModel.MessageContractAttributex).Any;

Willywillynilly