找人看看WEBrequest与WEBrespone的问题

[jin20000]

我照着<C#入门经典>(第三版)里面的29章29.4的例子写的,就是控件的名字和变量名有点不同,不知道为什么GETFILE就是要报错!!!!!!!!!
请大家帮我看看,问题在哪,谢谢!!!!!!!!!!!

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace FTPclient
{
    public partial class frmFTPClient : Form
    {
        private string serverdirectory ;

        public void FillDirectoryList(Stream stre)
        {
            StreamReader strr = new StreamReader(stre);
            string str = strr.ReadToEnd();
            string[] strl = str.Split('\n');
            listFile.DataSource = strl;
            strr.Close();
        }

        public frmFTPClient()
        {
            InitializeComponent();
        }


        private void btnOpen_Click(object sender, EventArgs e)
        {
            Cursor c = this.Cursor;
            FtpWebResponse respone = null;
            Stream stream = null;
            try
            {
                this.Cursor = Cursors.WaitCursor;
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(txtserver.Text);
                request.Credentials = new NetworkCredential(txtuser.Text, txtpwd.Text);
                request.Method = WebRequestMethods.Ftp.ListDirectory;
                respone = (FtpWebResponse)request.GetResponse();
                stream = respone.GetResponseStream();
                FillDirectoryList(stream);
                serverdirectory = null;
                btnGetFile.Enabled = false;
                btnOpenDirectory.Enabled = false;
            }
            catch( Exception ex)
            {
                MessageBox.Show("ERROE FTP Client");
            }
            finally
            {
                if (respone!=null)
                    respone.Close();
                if (stream!=null)
                    stream.Close();
                this.Cursor = c;
            }


        }

        private void btnOpenDirectory_Click(object sender, EventArgs e)
        {
            FtpWebResponse respone = null;
            Stream stream = null;
            try
            {
                string sub = listFile.SelectedValue.ToString().Trim();
                serverdirectory += @"/" + sub;
                Uri baseuri = new Uri(txtserver.Text);
                Uri uri = new Uri(baseuri, serverdirectory);

                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(uri);
                request.Credentials = new NetworkCredential(txtuser.Text, txtpwd.Text);
                request.Method = WebRequestMethods.Ftp.ListDirectory;
                respone = (FtpWebResponse)request.GetResponse();
                stream = respone.GetResponseStream();
                FillDirectoryList(stream);
                //serverdirectory = null;
                //btnGetFile.Enabled = false;
                //btnOpenDirectory.Enabled = false;
            }
            catch (Exception ex)
            {
                MessageBox.Show("ERROE FTP Client");
            }
            finally
            {
                if (respone != null)
                    respone.Close();
                if (stream != null)
                    stream.Close();
            }
        }

        private void btnGetFile_Click(object sender, EventArgs e)
        {
            FtpWebResponse respone = null;
            Stream instream = null;
            Stream outstream = null;
            try
            {
                Uri baseuri = new Uri(txtserver.Text);
                string name = listFile.SelectedValue.ToString().Trim();
                string fullname = serverdirectory + @"/" + name;
                Uri uri = new Uri(baseuri, fullname);

                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(txtserver.Text);
                request.Credentials = new NetworkCredential(txtuser.Text, txtpwd.Text);
                ///?????
                request.Method = WebRequestMethods.Ftp.DownloadFile;
                request.UseBinary = cbusebinary.Checked;
                respone = (FtpWebResponse)request.GetResponse();

                instream = respone.GetResponseStream();
                SaveFileDialog sf = new SaveFileDialog();
                sf.FileName = name;
                if (sf.ShowDialog() == DialogResult.OK)
                {
                    outstream = File.OpenWrite(sf.FileName);
                    byte[] buffer = new byte[4096];
                    int size = 0;
                    while ((size=instream.Read(buffer,0,4096))>0) 
                    {
                        outstream.Write(buffer, 0, size);
                    }
                }

                //FillDirectoryList(instream);
                //serverdirectory = null;
                //btnGetFile.Enabled = false;
                //btnOpenDirectory.Enabled = false;

            }
            catch (Exception ex)
            {
                MessageBox.Show("ERROE FTP Client");
            }
            finally
            {
                if (respone != null)
                    respone.Close();
                if (instream != null)
                    instream.Close();
                if (outstream != null)
                    outstream.Close();
            }
        }

        private void listFile_SelectedIndexChanged(object sender, EventArgs e)
        {
            btnGetFile.Enabled = true;
            btnOpenDirectory.Enabled = true;
        }
    }
}

[jin20000]

也就是btnGetFile_Click事件里,会有错误.
在执行"respone = (FtpWebResponse)request.GetResponse();"的时候,就会跳到
"
catch (Exception ex)
{
MessageBox.Show("ERROE FTP Client");
}
"
提示错误:请求的 URI 对于此 FTP 命令无效。

请教!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[jin20000]

哦,搞定了,