JSON Serialization with class inheritance from dictionary <T, V>

Question

I have a class that is currently inheriting from a dictionary, and then adds several properties of the first class class to it. Roughly speaking:

public class Foo : Dictionary<string, string> { public string Bar { get; set; } public string Baz { get; set; } } 

After serializing the instance of this object in JSON, however, it seems that the serializer only emits the key / value pairs that I saved in the dictionary. Even if I apply the DataMember attributes to the new properties of the first class, the JSON serializer does not seem to know what to do with them, but instead simply ignores them.

I assume that there is something fundamentally elementary that I am missing, but looking through code samples and documents on the JSON .net serializer, I found only trivial examples that do not quite correspond to what I am doing. All our other classes that come from some other base class do not seem to exhibit this problem, this is one that follows from a general vocabulary, in particular that gives us seizures.

[Change] If you do not move the dictionary to Foo as a property of the first class, is there a way to make this work? I assume the hang is that the serializer does not know what to “name” the dictionary to distinguish it from other members?

Answer 1

Perhaps in this case it would be better to use a solution based on composition:

 using System; using System.Collections.Generic; using System.Runtime.Serialization.Json; using System.IO; using System.Text; class Program { static void Main() { Foo foo = new Foo { Bar = "bar", Baz = "baz" }; foo.Items.Add("first", "first"); DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(Foo)); using (MemoryStream ms = new MemoryStream()) { serializer.WriteObject(ms, foo); Console.WriteLine(Encoding.Default.GetString(ms.ToArray())); } } } public class Foo { public Dictionary<string, string> Items { get; set; } public string Bar { get; set; } public string Baz { get; set; } public Foo() { this.Items = new Dictionary<string, string>(); } } 

Produces this conclusion:

{"Bar":"bar","Baz":"baz","Items":[{"Key":"first","Value":"first"}]}

Would this solve your problem as a workaround?