JsonTreeViewLoader

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using SampleServiceWinForm.Properties;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Drawing;
using System.Globalization;
using System.Windows.Forms;

namespace SampleServiceWinForm.Helpers
{
    public static class JsonTreeViewLoader
    {
        private static bool _initialized;

        #region *** [TreeViewToJson] ***

        public static string TreeViewToJson(this TreeView treeView)
        {
            Dictionary<string, dynamic> result = new Dictionary<string, dynamic>();

            TreeNodeCollection nodes = treeView.Nodes;
            foreach (TreeNode n in nodes)
            {
                result.Add(n.Text, PrintRecursive(n));
            }

            //return result;
            return JsonConvert.SerializeObject(result, Formatting.Indented).Replace("{}",string.Empty);
        }

        private static Dictionary<string, dynamic> PrintRecursive(this TreeNode treeNode)
        {
            Dictionary<string, dynamic> result = new Dictionary<string, dynamic>();

            foreach (TreeNode tn in treeNode.Nodes)
            {
                result.Add(tn.Text, PrintRecursive(tn));
            }
            return result;
        }

        #endregion *** [TreeViewToJson] ***

        #region *** [JsonToTreeView] ***

        public static void JsonToTreeView(this TreeView treeView, string json, string name)
        {
            if (string.IsNullOrWhiteSpace(json))
            {
                return;
            }

            treeView.Nodes.Clear();
            InitializeImages(treeView);

            var token = JToken.Parse(json);
            switch (token.Type)
            {
                case JTokenType.Array:
                    var objArray = JArray.Parse(json);
                    AddArrayNodes(objArray, name, treeView.Nodes);
                    break;

                case JTokenType.Object:
                    var objObject = JObject.Parse(json);
                    AddObjectNodes(objObject, name, treeView.Nodes);
                    break;

                default:
                    throw new NotImplementedException();
            }
        }

        private static void AddObjectNodes(JObject @object, string name, TreeNodeCollection parent)
        {
            var node = BuildBasicNode(@object.Type, name);
            parent.Add(node);
            foreach (var property in @object.Properties())
            {
                AddTokenNodes(property.Value, property.Name, node.Nodes);
            }
        }

        private static void AddArrayNodes(JContainer array, string name, TreeNodeCollection parent)
        {
            var node = BuildBasicNode(array.Type, name);
            parent.Add(node);
            for (var i = 0; i < array.Count; i++)
            {
                AddTokenNodes(array[i], $"[{i}]", node.Nodes);
            }
        }

        private static void AddTokenNodes(JToken token, string name, TreeNodeCollection parent)
        {
            switch (token)
            {
                case JValue value:

                    TreeNode node = BuildBasicNode(value.Type, $"{name}: {value.Value}");
                    parent.Add(node);
                    break;

                case JArray array:
                    AddArrayNodes(array, name, parent);
                    break;

                case JObject jObject:
                    AddObjectNodes(jObject, name, parent);
                    break;
            }
        }

        private static TreeNode BuildBasicNode(JTokenType type, string name)
        {
            var node = new TreeNode(name)
            {
                ImageKey = type.ToString(),
                SelectedImageKey = @"Selected"
            };
            return node;
        }

        private static void InitializeImages(this TreeView treeView)
        {
            if (_initialized) return;

            // Load the images in an ImageList.
            var imageList = new ImageList();
            var resourceSet = JsonTreeViewImages.ResourceManager.GetResourceSet(CultureInfo.InvariantCulture, true, false);
            if (resourceSet != null)
            {
                foreach (DictionaryEntry entry in resourceSet)
                {
                    if (entry.Value is Bitmap value)
                    {
                        imageList.Images.Add((string)entry.Key, value);
                    }
                }
            }

            // Assign the ImageList to the TreeView.
            treeView.ImageList = imageList;

            // Set the TreeView control's default image and selected image indexes.
            treeView.ImageIndex = 0;
            treeView.SelectedImageIndex = 1;

            // set our flag
            _initialized = true;
        }

        #endregion *** [JsonToTreeView] ***
    }
}