using System;

using System.Linq;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

            string jsonString = @"

            [

              {

                ""ID"": 17,

                ""Code"": ""1"",

                ""SupplierID"": 24,

                ""Date"": ""2018-07-04T10:16:37.107"",

                ""OrderDetails"": [

                  {

                    ""ID"": 17,

                    ""OrderID"": 17,

                    ""ItemID"": 5806,

                    ""Quantity"": 20000.0,

                    ""ConfirmQuantity"": 20000.0,

                    ""ConfirmDate"": ""2018-09-11T11:33:30.463"",

                    ""Deadline"": ""2018-07-22T00:00:00"",

                    ""IsCanceled"": false,

                    ""PersonnelID"": 667,

                    ""IsConfirmed"": false

                  },

                  {

                    ""ID"": 190,

                    ""OrderID"": 170,

                    ""ItemID"": 5806,

                    ""Quantity"": 20000.0,

                    ""ConfirmQuantity"": 20000.0,

                    ""ConfirmDate"": ""2018-09-11T11:33:30.463"",

                    ""Deadline"": ""2018-07-22T00:00:00"",

                    ""IsCanceled"": false,

                    ""PersonnelID"": 6670,

                    ""IsConfirmed"": false

                  }

                ]

              },

              {

                ""ID"": 19,

                ""Code"": ""2"",

                ""SupplierID"": 20,

                ""Date"": ""2018-07-14T13:25:50.03"",

                ""OrderDetails"": [

                  {

                    ""ID"": 18,

                    ""OrderID"": 19,

                    ""ItemID"": 15425,

                    ""Quantity"": 2100.0,

                    ""ConfirmQuantity"": 2100.0,

                    ""Deadline"": ""2018-07-18T00:00:00"",

                    ""IsCanceled"": false,

                    ""PersonnelID"": 445,

                    ""IsConfirmed"": false

                  }

                ]

              }

            ]";

​

            var namesToKeep = new string[] { "ID", "Code", "OrderDetails", "ItemID", "Quantity" };

            var jArray = JArray.Parse(jsonString);

            foreach (var prop in jArray.Descendants().OfType<JProperty>().ToList())

            {

                if (!namesToKeep.Contains(prop.Name))

                    prop.Remove();

            }

            jsonString = jArray.ToString();

            Console.WriteLine(jsonString);

    }

}