C#如何打开并读取usb的文件目录

using System;using System.Collections;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.IO;using System.Linq;using System.Text;using System.Threading;using System.Threading.Tasks;using System.Windows.Forms; namespace usbText{ public partial class Form1 : Form { DriveInfo Tdriver = null; public Form1() { InitializeComponent(); } protected override void WndProc(ref Message m) { if (m.Msg == 0x0219)//WM_DEVICECHANGE { switch (m.WParam.ToInt32()) {  case 0x8000://DBT_DEVICEARRIVAL  {  MessageBox.Show("设备插入");  string[] dirs = Environment.GetLogicalDrives(); //取得所有的盘符   foreach (string dir in dirs)  {   Tdriver = new DriveInfo(dir);   if (Tdriver.DriveType == DriveType.Removable)   {   {   while (Tdriver.IsReady == false)   {   Thread.Sleep(500);   }   try   {   string PSTR = "";   PSTR += "磁盘名称：" + Tdriver.Name + "/r/n";   PSTR += "磁盘卷标：" + Tdriver.VolumeLabel + "/r/n";   PSTR += "文件系统：" + Tdriver.DriveFormat + "/r/n";   PSTR += "剩余大小：" + Tdriver.AvailableFreeSpace.ToString() + "/r/n";   PSTR += "总体容量：" + Tdriver.TotalSize.ToString() + "/r/n";   PSTR += "总体容量：" + Tdriver.RootDirectory.ToString() + "/r/n";   MessageBox.Show(PSTR);   }   catch   {   MessageBox.Show("error");   }   }   }  }   break;  }  case 0x8004://DBT_DEVICEREMOVECOMPLETE  {  MessageBox.Show("设备拔出");  break;  } } } base.WndProc(ref m); } private void AddToTreeView(TreeNode node) { treeView1.Nodes.Add(node); treeView1.Refresh(); } internal void LoadFolderFileList(string path, TreeNode nodes) { string[] dirs = Directory.GetDirectories(path); string[] files = Directory.GetFiles(path); for (int i = 0; i < dirs.Length; i++) { string[] info = new string[4]; DirectoryInfo di = new DirectoryInfo(dirs[i]); TreeNode node = new TreeNode(di.Name); node.Tag = di.FullName; try {  if (di.GetDirectories().Length > 0 || di.GetFiles().Length > 0)  {  LoadFolderFileList(di.FullName, node);  }  else  {  continue;  } } catch {  continue; } nodes.Nodes.Add(node); } for (int i = 0; i < files.Length; i++) { FileInfo fi = new FileInfo(files[i]); TreeNode node = new TreeNode(fi.Name); node.Tag = fi.FullName; nodes.Nodes.Add(node); } } private void button1_Click(object sender, EventArgs e) { if (Tdriver != null) { TreeNode node = new TreeNode(); LoadFolderFileList(Tdriver.RootDirectory.ToString(), node); treeView1.Nodes.Add(node); } } }}