public partial class Form1 : Form
    {
        string path = @"F:/學習文件";//遞歸查找樹狀目錄
        public Form1()
        {遞歸查找樹狀目錄
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            LoadTree(path);
        }

 public void LoadTree(string path, TreeNode node=null)

        {           

string[] dirs = Directory.GetDirectories(path);//獲取子目錄

            foreach (string dir in dirs)

            {

                  TreeNode node1 = new TreeNode(Path.GetFileName(dir));

                //TreeNode node1 = new TreeNode(dir);//文件所有路徑

                if (node == null)

                {

                    treeView1.Nodes.Add(node1);

                }

                else

                {

                    node.Nodes.Add(node1);

                }

 if (Directory.GetDirectories(dir).Length > 0)
                {
                    LoadTree(dir, node1);
                }
            }
        }
    }
}