TreeView Control logic issue in c#

            using System;
            using System.Collections.Generic;
            using System.ComponentModel;
            using System.Data;
            using System.Drawing;
            using System.Linq;
            using System.Text;
            using System.Threading.Tasks;
            using System.Windows.Forms;
            using System.IO;
            namespace tree_browse
            {
            public partial class Form1 : Form
            {
                 string strSearchPath = string.Empty;
                 public Form1()
                 {
                     InitializeComponent();
                 }
                 private void button1_Click(object sender, EventArgs e)
                 {
                       FolderBrowserDialog folderBrowserDialog = new FolderBrowserDialog();
                       folderBrowserDialog.SelectedPath = strSearchPath;
                       if (folderBrowserDialog.ShowDialog() == DialogResult.OK)
                       {
                           Properties.Settings.Default.Save();
                           strSearchPath = folderBrowserDialog.SelectedPath;
                           GetTree(strSearchPath);
                       }
                 }
                 void GetTree(string strSearchPath)
                 {
                      treeView1.Nodes.Clear();
                      SetNode(treeView1, strSearchPath);
                      treeView1.TopNode.Expand();
                  }
                 void SetNode(TreeView treeName, string path)
                  {
                       DirectoryInfo dirInfo = new DirectoryInfo(path);
                       TreeNode node = new TreeNode(dirInfo.Name);
                       node.Tag = dirInfo;
                       GetFolders(dirInfo, node);
                       GetFiles(dirInfo, node);
                        treeName.Nodes.Add(node);
                  }
                  void GetFolders(DirectoryInfo d, TreeNode node)
                  {
                     try
                       {
                          DirectoryInfo[] dInfo = d.GetDirectories();
                          if (dInfo.Length > 0)
                          {
                               TreeNode treeNode = new TreeNode();
                               foreach (DirectoryInfo driSub in dInfo)
                               {
                                   treeNode = node.Nodes.Add(driSub.Name, driSub.Name, 0, 0);
                                   GetFiles(driSub, treeNode);
                                   GetFolders(driSub, treeNode);
                               }
                           }
                       }
                      catch (Exception ex) { }
                  }
                void GetFiles(DirectoryInfo d, TreeNode node)
                {
                    //if you want to search .doc or docx file then:
                    // var files = d.GetFiles("*.doc*");
                    var files = d.GetFiles("*.*");
                    FileInfo[] subfileInfo = files.ToArray<FileInfo>();
                    if (subfileInfo.Length > 0)
                    {
                         for (int j = 0; j < subfileInfo.Length; j++)
                         {
                         //Checking for Hiddend files
                         bool isHidden = ((File.GetAttributes(subfileInfo[j].FullName) &      FileAttributes.Hidden) == FileAttributes.Hidden);
                              if (!isHidden)
                              {
                                   TreeNode treeNode = new TreeNode();
                                   string path = subfileInfo[j].FullName;
                                   string name = subfileInfo[j].Name;
                                   treeNode = node.Nodes.Add(path, name);
                               }
                          }
                    }
            }
      }
}