System.Windows.Forms.TreeView.Refresh C# (CSharp) Method

        public override void Refresh()
        {
            _nodeList = new List<TreeNode>();
            scrollNodeList = new List<TreeNode>();

            ProccesNode(root);
            _UpdateScrollList();
            _FixScrollIndex();
        }

        public void FillTree()
        {
            //FillTreeView
            tree.FillOneLevelTree(treeView1);


            ImageList imgList = new ImageList();

            imgList.ColorDepth = ColorDepth.Depth32Bit;
            imgList.Images.Add(new Icon(@"D:\Working\ALLinONE_Manager\Coding\ALLinONE_Manager\AIOIcon\folder3.ico"));
            imgList.Images.Add(new Icon(@"D:\Working\ALLinONE_Manager\Coding\ALLinONE_Manager\AIOIcon\file1.ico"));
            imgList.Images.Add(new Icon(@"D:\Working\ALLinONE_Manager\Coding\ALLinONE_Manager\AIOIcon\folder2_green.ico"));
            treeView1.ImageList          = imgList;
            treeView1.SelectedImageIndex = 2;

            treeView1.Nodes[0].Expand();
            treeView1.SelectedNode = treeView1.Nodes[0];
            treeView1.Refresh();

            //FillListView
            listView1.SmallImageList = imgList;
            listView1.LargeImageList = imgList;

            timer.Stop();
            lblTotal.Text = "Folders: " + tree.FoldersCount + " Files: " + tree.FilesCount + " List: " + lstDirectory.Items.Count + " Elapsed: " + timer.Duration + " (s)";
        }