How to de/serialize System.Drawing.Size to object using JSON.Net?

Question

I have absolutely no idea how to do this.

Sample class that I use:

class MyClass
{

    private Size _size = new Size(0, 0);

    [DataMember]
    public Size Size
    {
        get { return _size; }
        set { _size = value; }
    }
}

This getting serialized to {size: "0, 0"}. What I need is {size: {width: 0, height: 0}}.

Any help is appreciated, thanks.

Answer 1

Here is a simple JsonConverter you can use to make System.Drawing.Size serialize the way you want:

using System;
using System.Drawing;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

public class SizeJsonConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Size));
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        Size size = (Size)value;
        JObject jo = new JObject();
        jo.Add("width", size.Width);
        jo.Add("height", size.Height);
        jo.WriteTo(writer);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject jo = JObject.Load(reader);
        return new Size((int)jo["width"], (int)jo["height"]);
    }
}

To use the converter, you just need to pass an instance of it to JsonConvert.SerializeObject as shown below:

MyClass widget = new MyClass { Size = new Size(80, 24) };
string json = JsonConvert.SerializeObject(widget, new SizeJsonConverter());
Console.WriteLine(json);

This will give the following output:

{"Size":{"width":80,"height":24}}

Deserialization works the same way; pass an instance of the converter to DeserializeObject<T>:

string json = @"{""Size"":{""width"":80,""height"":24}}";
MyClass c = JsonConvert.DeserializeObject<MyClass>(json, new SizeJsonConverter());
Console.WriteLine(c.Size.Width + "x" + c.Size.Height);

Output:

80x24