Deserializing such that a field is an empty list rather than null

Question

If I have a class like this:

[DataContract(Name = \"\", Namespace = \"\")]
public class MyDataObject
{
    [DataMember(Name = \"NeverNull\")]
    public ILis         


        

Answer 1

Initialization of IList<int>with new int[0] will help you out! Its the solution that gives me the best results.

Answer 2

Perhaps add a post-serialization callback that checks this at the end of deserialization?

[DataContract(Name = "", Namespace = "")]
public class MyDataObject
{
    [OnDeserialized]
    public void OnDeserialized(StreamingContext context)
    {
        if (MyInts == null) MyInts = new List<int>();
    }
    [DataMember(Name = "NeverNull")]
    public IList<int> MyInts { get; set; }
}

Note also that JsonConvert (unlike DataContractSerializer) executes the default constructor, so usually you could also have just added a default constructor:

    public MyDataObject()
    {
        MyInts = new List<int>();
    }

however, in this case the explict "NeverNull":null changes it back to null during deserialization, hence why I've used a callback above instead.