Question

Tested out the same code in Visual Studio on Windows to make sure.

Using MonoDevelop on Mac with Mono framework 3.0.1. I’m trying to serialize objects to JSON and need to populate some properties in the OnSerializing event by assigning System.Runtime.Serialization.OnSerializingAttribute to a method. However, mono framework does not appear to be calling into the method. None of the other serialization events work either. Simplified the code for example:

using System;
using System.IO;
using System.Runtime.Serialization.Json;
using System.Runtime.Serialization;

namespace MyApp
{
    class MainClass
    {
        public static void Main (string[] args)
        {
            Cereal specialK = new Cereal();

            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Cereal));

            specialK.TheValue="This is a what?";

            MemoryStream stm = new MemoryStream();
            ser.WriteObject(stm, specialK);
            string json = System.Text.Encoding.UTF8.GetString(stm.ToArray());

            Console.WriteLine(json);
            Console.ReadLine();

        }
    }

    [DataContract]
    class Cereal
    {
        [DataMember(Name="set_on_serialize")]
        private string _setOnSerialize = string.Empty;

        public Cereal() { }

        [DataMember(Name = "out_value")]
        public string TheValue
        {
            get;
            set;
        }

        [OnSerializing]
        void OnSerializing(StreamingContext content)
        {
            this._setOnSerialize = "A brick!";
        }
    }
}

In Visual Studio, the output is:
{“out_value”:”This is a what?”,”set_on_serialize”:”A brick!”}

In MonoDevelop on Mac, I get:
{“out_value”:”This is a what?”,”set_on_serialize”:””}

Mono is not calling the OnSerializing event for some reason.

Has anyone else encountered this or can you help explain why the code fails?

Thanks

Answer 1

This was a bug in Mono, I just fixed this for you 🙂