C# object to JSON string

Question

Hi

I'm left with an object which contains a list of items and a string - similar to this example:

 static void Main(string[] args)
        {
            Item i1 = new Item
            {
                Name = "test1",
                Value = "result1"
            };

            Item i2 = new Item
            {
                Name = "test2",
                Value = "result2"
            };

            ReturnData returnData = new ReturnData();

            List<Item> items = new List<Item>();

            items.Add(i1);
            items.Add(i2);

            returnData.Type = "type1";
            returnData.Items = items;

        }



        class ReturnData
        {

            internal string Type { get; set; }
            internal List<Item> Items { get; set; }

        }

        public class Item
        {

            public string Name { get; set; }

            public string Value { get; set; }
        }

How do I convert returnData to a json string?

I have tried:

var json = JsonConvert.SerializeObject(returnData);

Console.WriteLine(json);

But this did not work.

Many thanks
Paul

Answer 1

In ReturnData make the members public. When I do I get:

{"Type":"type1","Items":[{"Name":"test1","Value":"result1"},{"Name":"test2","Value":"result2"}]}

So you almost had it and now you do have it.

A .NET Fiddle for this is at ObjectToJSON.

Answer 2

When there are internal properties mark them as a JsonProperty, otherwise go with SimpleSamples recommendation.

using System.Collections.Generic;
using System.Diagnostics;
using Newtonsoft.Json;

namespace ObjectToJson
{
    class Program
    {
        static void Main(string[] args)
        {
            var i1 = new Item
            {
                Name = "test1",
                Value = "result1"
            };

            var i2 = new Item
            {
                Name = "test2",
                Value = "result2"
            };

            ReturnData returnData = new ReturnData();

            var items = new List<Item> {i1, i2};


            returnData.Type = "type1";
            returnData.Items = items;

            var json = JsonConvert.SerializeObject(returnData, Formatting.Indented);

            Debug.WriteLine(json);

        }
    }
    class ReturnData
    {
        [JsonProperty]
        internal string Type { get; set; }
        [JsonProperty]
        internal List<Item> Items { get; set; }
    }

    public class Item
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }
}

Output

{
  "Type": "type1",
  "Items": [
    {
      "Name": "test1",
      "Value": "result1"
    },
    {
      "Name": "test2",
      "Value": "result2"
    }
  ]
}