C#使用FTP釋出檔案或資料夾
一、選擇一個已有的ftp站點，要求已知登入資訊。如果沒有，則本地新增ftp站點，具體新增ftp站點的教程如下，百度上有很多類似教程：

https://jingyan.baidu.com/article/dca1fa6f479469f1a4405292.html

二、選擇正確的FTP操作庫。可選擇系統自帶的FTP庫，或者其他庫如（推薦用FluentFTP，Nuget裡可以下載到）

FluentFTP:  https://www.nuget.org/packages/FluentFTP

三、具體程式碼

        //用於驗證登入資訊是否正確
        private
 
 bool validateLogin()
        {
            try
            {
                var Ip = tbxIp.Text;
                var User = tbxUser.Text;
                var Psw = tbxPwb.Password;
                var uriStr = $"ftp://{Ip}";
                var request = FtpWebRequest.Create(new Uri(_ftpPath));
                request.Credentials = new
 
 NetworkCredential(_user, _password);
                request.Method = WebRequestMethods.Ftp.ListDirectory;
                var response = request.GetResponse();
                response.Close();
                request.Abort();
                return true;
            }
            catch (Exception ex)
            {
                //沒有登入上
 

            }
            return false;
        }


        //獲取指定伺服器路徑下的檔案/資料夾路徑，此處的path應該是ftp://xxx.xxx.xxx.xx/ABC/DEF的資料夾路徑
        private List<string> GetFolders(string path)
        {
            var lstFolders = new List<string>();
            try
            {
                var ftpGetFolders = (FtpWebRequest)WebRequest.Create(new Uri(path));
                ftpGetFolders.Credentials = new NetworkCredential(_user, _password);
                ftpGetFolders.Method = WebRequestMethods.Ftp.ListDirectoryDetails;//所有的檔案列表，包括檔案和資料夾
                var response = ftpGetFolders.GetResponse();
                var sReader = new StreamReader(response.GetResponseStream());//獲取返回的位元組流並解析
                string line = sReader.ReadLine();
                while (line != null)
                {
                    if (line.Contains("<DIR>"))//所有的資料夾都有這個標誌，但檔案也有可能有這個命名，還是比較蛋疼的
                    {
                        string msg = line.Substring(line.LastIndexOf("<DIR>") + 5).Trim();
                        lstFolders.Add(msg);
                    }
                    line = sReader.ReadLine();
                }
                sReader.Close();
                response.Close();
                ftpGetFolders.Abort();
            }
            catch (Exception ex)
            {
                //ignore
            }
            return lstFolders;
        }


        //建立ftp資料夾，ftpFolderpath為以ftp://開頭的資料夾完整路徑
        private bool CreateFolder(string ftpFolderpath)
        {
            try
            {
                var ftpMakeFolder = (FtpWebRequest)WebRequest.Create(new Uri(ftpFolderpath));
                ftpMakeFolder.Credentials = new NetworkCredential(_user, _password);
                ftpMakeFolder.Method = WebRequestMethods.Ftp.MakeDirectory;
                var response = ftpMakeFolder.GetResponse();
                response.Close();
                ftpMakeFolder.Abort();
                return true;
            }
            catch (Exception)
            {//ignore
            }
            return false;

        }


        //釋出檔案，FilePath為本地的檔案路徑
        private bool PublishFile(string FilePath)
        {
            try
            {
                var newPath = @"ftp://" + Ip + Loc + $"/{Path.GetFileName(FilePath)}";//釋出的具體路徑，詳細到檔名
                FtpWebRequest FTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(newPath));
                FTP.Method = WebRequestMethods.Ftp.UploadFile;//選擇上傳檔案方法
                FTP.Credentials = new NetworkCredential(User, Psw);
                var fs = new FileStream(FilePath, FileMode.Open);
                int buffLength = 2048;
                byte[] buff = new byte[buffLength];
                int contentLen = 0;
                var strm = FTP.GetRequestStream();
                WaitHelper.StartWaiting();
                contentLen = fs.Read(buff, 0, buffLength);
                while (contentLen != 0)
                {
                    strm.Write(buff, 0, contentLen);
                    contentLen = fs.Read(buff, 0, buffLength);
                }
                strm.Close();
                fs.Close();
                WaitHelper.CloseWaiting();
                FTP.Abort();
                return true;
            }
            catch (Exception ex)
            {
                ControlUtility.ShowWarningMsgbox($"上傳失敗");
                return false;
            }
        }

本文給出的只是一個基本操作，並沒有做細節上的處理。FTP類中還有許多其他的方法有待學習。