/// <summary>
/// 获取地址下的列表
/// </summary>
/// <returns></returns>
public static string[] GetFileList()
{
string[] downloadFiles;
StringBuilder result = new StringBuilder();
FtpWebRequest reqFTP;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/"));
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;
WebResponse response = reqFTP.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string line = reader.ReadLine();
while (line != null)
{
result.Append(line);
result.Append("\n");
line = reader.ReadLine();
}
// to remove the trailing ‘\n‘
result.Remove(result.ToString().LastIndexOf(‘\n‘), 1);
reader.Close();
response.Close();
return result.ToString().Split(‘\n‘);
}
catch (Exception ex)
{
//System.Windows.Forms.MessageBox.Show(ex.Message);
downloadFiles = null;
return downloadFiles;
}
}
/// <summary>
/// 上传
/// </summary>
/// <param name="filename">文件流</param>
private static void Upload(string filename)
{
FileInfo fileInf = new FileInfo(filename);
string uri = "ftp://" + ftpServerIP + "/" + fileInf.Name;
FtpWebRequest reqFTP;

// 根据uri创建FtpWebRequest对象
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileInf.Name));

// ftp用户名和密码
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

// 默认为true，连接不会被关闭
// 在一个命令之后被执行
reqFTP.KeepAlive = false;

// 指定执行什么命令
reqFTP.Method = WebRequestMethods.Ftp.UploadFile;

// 指定数据传输类型
reqFTP.UseBinary = true;

// 上传文件时通知服务器文件的大小
reqFTP.ContentLength = fileInf.Length;

// 缓冲大小设置为2kb
int buffLength = 2048;

byte[] buff = new byte[buffLength];
int contentLen;

// 打开一个文件流 (System.IO.FileStream) 去读上传的文件
FileStream fs = fileInf.OpenRead();
try
{
// 把上传的文件写入流
Stream strm = reqFTP.GetRequestStream();

// 每次读文件流的2kb
contentLen = fs.Read(buff, 0, buffLength);

// 流内容没有结束
while (contentLen != 0)
{
// 把内容从file stream 写入 upload stream
strm.Write(buff, 0, contentLen);

contentLen = fs.Read(buff, 0, buffLength);
}

// 关闭两个流
strm.Close();
fs.Close();
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// 下载
/// </summary>
/// <param name="filePath">下载地址</param>
/// <param name="fileName">下载文件的名称(下载后名称)</param>
private static void Download(string filePath, string fileName)
{
FtpWebRequest reqFTP;

try
{
FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);

reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileName));

reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;

reqFTP.UseBinary = true;

reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

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 ex;
}
}

参考 https://www.cnblogs.com/webabcd/archive/2007/01/21/626242.html

C# FTP 访问、下载、上传