初学者求助：如何得到node的路径

using System;
using System.Collections.Generic;
using using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using using System.Diagnostics;

namespace tREEVIEW
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
        {
            string selectnodepath = e.Node.FullPath.ToString();
            


        }

        private void Form1_Load(object sender, EventArgs e)
        {
            TreeNode root = new TreeNode();

            //根目录名称
         
         

            //根目录路径
            GetFiles("c:\\test", root);
            treeView1.Nodes.Add(root);
            root.Tag = root.FullPath;
            
        }


        public void GetFiles(string filePath, TreeNode node)
        {
            DirectoryInfo folder = new DirectoryInfo(filePath);
            node.Text = folder.Name;
            node.Tag = folder.FullName;            
            
            
            FileInfo[] chldFiles = folder.GetFiles("*.*");
            foreach (FileInfo chlFile in chldFiles)
            {
                TreeNode chldNode = new TreeNode();
                chldNode.Text = chlFile.Name;
                chldNode.Tag = chlFile.FullName;
                node.Nodes.Add(chldNode);
            }

            DirectoryInfo[] chldFolders = folder.GetDirectories();
            foreach (DirectoryInfo chldFolder in chldFolders)
            {
                TreeNode chldNode = new TreeNode();
                chldNode.Text = folder.Name;
                chldNode.Tag = folder.FullName;
                node.Nodes.Add(chldNode);
                GetFiles(chldFolder.FullName, chldNode);
           

               
            }

        }

        private void button1_Click(object sender, EventArgs e)
        {

            MessageBox.Show(treeView1.SelectedNode.FullPath.ToString());
            string showsearch = Path.GetDirectoryName(treeView1.SelectedNode.FullPath.ToString());
            DirectoryInfo test = new DirectoryInfo(showsearch);
            DirectoryInfo[] searchinfo = test.GetDirectories();
            foreach (DirectoryInfo news in searchinfo)
            {
                if (news.Name.Contains(textBox1.Text))
                {
                    //treeView1.Nodes.Add(news.Name);
                    listBox1.Items.Add(news.Name);
                }
               

            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            ProcessStartInfo proc = new ProcessStartInfo();
            proc.UseShellExecute = true;
            proc.FileName = "C:\\test.bat";
            proc.Verb = "runas";
            try
            {
                Process.Start(proc);
            }
            catch
            {
                return;
            }
            Application.Exit();  // Quit itself

            if (treeView1.SelectedNode.IsSelected==true)
            {
                Process.Start(treeView1.SelectedNode.ToString());
            }
            else
            {
                Process.Start(listBox1.SelectedItem.ToString());
            }

        }

        private void listBox1_Doubleclick(object sender, EventArgs e)
        {
            foreach (DirectoryInfo f in new DirectoryInfo(listBox1.SelectedItem.ToString()).GetDirectories())
            {

                MessageBox.Show(listBox1.SelectedItem.ToString());
                listBox1.Items.Add(f.FullName);

            }
        }
    }

}