如下资料是关于C#自定义FTP访问类的代码，应该对各朋友有帮助。

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;

namespace DotNet.Utilities
{
public class FTPHelper
{
#region 字段
string ftpURI;
string ftpUserID;
string ftpServerIP;
string ftpPassword;
string ftpRemotePath;
#endregion

public FTPHelper(string FtpServerIP, string FtpRemotePath, string FtpUserID, string FtpPassword)
{
ftpServerIP = FtpServerIP;
ftpRemotePath = FtpRemotePath;
ftpUserID = FtpUserID;
ftpPassword = FtpPassword;
}

public void Upload(string filename)
{
FileInfo fileInf = new FileInfo(filename);
FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileInf.Name));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
reqFTP.KeepAlive = false;
reqFTP.UseBinary = true;
reqFTP.ContentLength = fileInf.Length;
int buffLength = 2048;
byte[] buff = new byte[buffLength];
int contentLen;
FileStream fs = fileInf.OpenRead();
try
{
Stream strm = reqFTP.GetRequestStream();
contentLen = fs.Read(buff, 0, buffLength);
while (contentLen != 0)
{
strm.Write(buff, 0, contentLen);
contentLen = fs.Read(buff, 0, buffLength);
}
strm.Close();
fs.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}

public void Download(string filePath, string fileName)
{
try
{
FileStream outputStream = new FileStream(filePath + "\" + fileName, FileMode.Create);
FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
reqFTP.UseBinary = true;
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
long cl = response.ContentLength;
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = ftpStream.Read(buffer, 0, bufferSize);
while (readCount > 0)
{
outputStream.Write(buffer, 0, readCount);
readCount = ftpStream.Read(buffer, 0, bufferSize);
}
ftpStream.Close();
outputStream.Close();
response.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}

public void Delete(string fileName)
{
try
{
FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.DeleteFile;
reqFTP.KeepAlive = false;
string result = String.Empty;
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
long size = response.ContentLength;
Stream datastream = response.GetResponseStream();
StreamReader sr = new StreamReader(datastream);
result = sr.ReadToEnd();
sr.Close();
datastream.Close();
response.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}

public string[] GetFilesDetailList()
{
try
{
StringBuilder result = new StringBuilder();
FtpWebRequest ftp;
ftp = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI));
ftp.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
ftp.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
WebResponse response = ftp.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string line = reader.ReadLine();
line = reader.ReadLine();
line = reader.ReadLine();
while (line != null)
{
result.Append(line);
result.Append("n");
line = reader.ReadLine();
}
result.Remove(result.ToString().LastIndexOf("n"), 1);
reader.Close();
response.Close();
return result.ToString().Split('n');
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}

private string[] GetAllList(string url)
{
List<string> list = new List<string>();
FtpWebRequest req = (FtpWebRequest)WebRequest.Create(new Uri(url));
req.Credentials = new NetworkCredential(ftpPassword, ftpPassword);
req.Method = WebRequestMethods.Ftp.ListDirectory;
req.UseBinary = true;
req.UsePassive = true;
try
{
using (FtpWebResponse res = (FtpWebResponse)req.GetResponse())
{
using (StreamReader sr = new StreamReader(res.GetResponseStream()))
{
string s;
while ((s = sr.ReadLine()) != null)
{
list.Add(s);
}
}
}
}
catch (Exception ex)
{
throw (ex);
}
return list.ToArray();
}

public string[] GetFileList(string url)
{
StringBuilder result = new StringBuilder();
FtpWebRequest reqFTP;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(url));
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpPassword, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
WebResponse response = reqFTP.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string line = reader.ReadLine();
while (line != null)
{

if (line.IndexOf("<DIR>") == -1)
{
result.Append(Regex.Match(line, @"[S]+ [S]+", RegexOptions.IgnoreCase).Value.Split(' ')[1]);
result.Append("n");
}
line = reader.ReadLine();
}
result.Remove(result.ToString().LastIndexOf('n'), 1);
reader.Close();
response.Close();
}
catch (Exception ex)
{
throw (ex);
}
return result.ToString().Split('n');
}

public bool FileExist(string RemoteFileName)
{
foreach (string str in fileList)
{
if (str.Trim() == RemoteFileName.Trim())
{
return true;
}
}
return false;
}

public void MakeDir(string dirName)
{
FtpWebRequest reqFTP;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + dirName));
reqFTP.Method = WebRequestMethods.Ftp.MakeDirectory;
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
ftpStream.Close();
response.Close();
}
catch (Exception ex)
{ }
}

public long GetFileSize(string filename)
{
FtpWebRequest reqFTP;
long fileSize = 0;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + filename));
reqFTP.Method = WebRequestMethods.Ftp.GetFileSize;
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
fileSize = response.ContentLength;
ftpStream.Close();
response.Close();
}
catch (Exception ex)
{ }
return fileSize;
}

public void ReName(string currentFilename, string newFilename)
{
FtpWebRequest reqFTP;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + currentFilename));
reqFTP.Method = WebRequestMethods.Ftp.Rename;
reqFTP.RenameTo = newFilename;
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
ftpStream.Close();
response.Close();
}
catch (Exception ex)
{ }
}

public void MovieFile(string currentFilename, string newDirectory)
{
ReName(currentFilename, newDirectory);
}

public void GotoDirectory(string DirectoryName, bool IsRoot)
{
if (IsRoot)
{
ftpRemotePath = DirectoryName;
}
else
{
ftpRemotePath += DirectoryName + "/";
}
}
}
}