Deserialize array values to .NET properties using DataContractJsonSerializer

Question

I\'m working with the DataContractJsonSerializer in Silverlight 4 and would like to deserialize the following JSON:

{
    \"collectionname\":\"Books\",
    \         


        

Answer 1

I find your question very interesting. So I have to spent my time in trying to solve the problem. Currently I received an example which can serialize and deserealize JSON data like following:

{
  "collectionname":"Books",
  "collectionitems":[
    {"book":["12345-67890",201,"Book One"]},
    {"book":["09876-54321",45,"Book Two"]}
  ]
}

the corresponding code of a small console application:

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization;
using System.Security.Permissions;

namespace DataContractJsonSerializer {
    [DataContract]
    class BookCollection {
        [DataMember (Order = 0)]
        public string collectionname { get; set; }
        [DataMember (Order = 1)]
        public List collectionitems { get; set; }
    }

    [Serializable]
    [KnownType (typeof (object[]))]
    class Book: ISerializable {
        public string Id { get; set; }
        public int NumberOfPages { get; set; }
        public string Title { get; set; }

        public Book () { }

        [SecurityPermissionAttribute (SecurityAction.Demand, Flags = SecurityPermissionFlag.SerializationFormatter)]
        protected Book (SerializationInfo info, StreamingContext context) {
            // called by DataContractJsonSerializer.ReadObject
            Object[] ar = (Object[]) info.GetValue ("book", typeof (object[]));

            this.Id = (string)ar[0];
            this.NumberOfPages = (int)ar[1];
            this.Title = (string)ar[2];
        }

        [SecurityPermission (SecurityAction.Demand, SerializationFormatter = true)]
        public void GetObjectData (SerializationInfo info, StreamingContext context) {
            // called by DataContractJsonSerializer.WriteObject
            object[] ar = new object[] { (object)this.Id, (object)this.NumberOfPages, (object)this.Title };
            info.AddValue ("book", ar);
        }
    }

    class Program {
        static readonly string testJSONdata = "{\"collectionname\":\"Books\",\"collectionitems\":[{\"book\":[\"12345-67890\",201,\"Book One\"]},{\"book\":[\"09876-54321\",45,\"Book Two\"]}]}";

        static void Main (string[] args) {
            BookCollection test = new BookCollection () {
                collectionname = "Books",
                collectionitems = new List {
                    new Book() { Id = "12345-67890", NumberOfPages = 201, Title = "Book One"},
                    new Book() { Id = "09876-54321", NumberOfPages = 45, Title = "Book Two"},
                }
            };

            MemoryStream memoryStream = new MemoryStream ();
            System.Runtime.Serialization.Json.DataContractJsonSerializer ser =
                new System.Runtime.Serialization.Json.DataContractJsonSerializer (typeof (BookCollection));
            memoryStream.Position = 0;
            ser.WriteObject (memoryStream, test);

            memoryStream.Flush();
            memoryStream.Position = 0;
            StreamReader sr = new StreamReader(memoryStream);
            string str = sr.ReadToEnd ();
            Console.WriteLine ("The result of custom serialization:");
            Console.WriteLine (str);

            if (String.Compare (testJSONdata, str, StringComparison.Ordinal) != 0) {
                Console.WriteLine ("Error in serialization: unexpected results.");
                    return;
            }

            byte[] jsonDataAsBytes = System.Text.Encoding.GetEncoding ("iso-8859-1").GetBytes (testJSONdata);
            MemoryStream stream = new MemoryStream (jsonDataAsBytes);
            stream.Position = 0;
            BookCollection p2 = (BookCollection)ser.ReadObject (stream);
        }
    }
}

I don't yet tested this approach under Silverlight 4.