using System;

using System.Data;  

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        DataTable table = new DataTable();

        DataColumn idColumn = new DataColumn("id", typeof(int));

        idColumn.AutoIncrement = true;

​

        DataColumn itemColumn = new DataColumn("item");

        table.Columns.Add(idColumn);

        table.Columns.Add(itemColumn);

​

​

        for (int i = 0; i < 2; i++)

        {

            DataRow newRow = table.NewRow();

            newRow["item"] = "item " + i;

            table.Rows.Add(newRow);

        }

​

​

        string json = JsonConvert.SerializeObject(table, Formatting.Indented);

​

        Console.WriteLine(json);

    }

}