优化后的 FtpClient 代码

优化说明问题解决：

1. 目录已存在报错：增强错误处理，忽略多种目录已存在状态码。
2. UI 卡顿：移除 Thread.Sleep，用 async/await 和并行任务，线程安全更新 UI。
3. 异步上传：限制并发任务（5），提升效率。
4. 安全性：支持证书指纹验证，强制 TLS 1.2/1.3。
5. 用户体验：禁用按钮防重复点击，显示进度，弹窗提示。

优化后的 FtpClient 代码：csharp

using System; using System.IO; using System.Net; using System.Net.Security; using System.Security.Cryptography.X509Certificates; using System.Threading.Tasks; namespace FTP客户端Demo { public class FtpClient { private readonly string _host, _username, _password, _trustedThumbprint; private readonly bool _useFtps; public FtpClient(string host, string username, string password, bool useFtps = true, string trustedThumbprint = null) { _host = host.TrimEnd('/'); _username = username; _password = password; _useFtps = useFtps; _trustedThumbprint = trustedThumbprint; ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls13; } public async Task UploadFileAsync(string localFilePath, string remoteFilePath, bool createDirectories = true, IProgress<int> progress = null) { if (!File.Exists(localFilePath)) throw new FileNotFoundException($"本地文件 {localFilePath} 不存在"); var request = (FtpWebRequest)WebRequest.Create($"{_host}/{remoteFilePath}"); request.Method = WebRequestMethods.Ftp.UploadFile; request.Credentials = new NetworkCredential(_username, _password); request.UseBinary = true; request.UsePassive = true; request.KeepAlive = false; if (_useFtps) { request.EnableSsl = true; ServicePointManager.ServerCertificateValidationCallback = ValidateServerCertificate; } if (createDirectories) { var directoryPath = Path.GetDirectoryName(remoteFilePath)?.Replace("\\", "/"); if (!string.IsNullOrEmpty(directoryPath)) await CreateDirectoryAsync(directoryPath); } using (var fileStream = File.OpenRead(localFilePath)) using (var requestStream = await request.GetRequestStreamAsync()) { byte[] buffer = new byte[8192]; long totalBytes = fileStream.Length, bytesSent = 0; int bytesRead; while ((bytesRead = await fileStream.ReadAsync(buffer, 0, buffer.Length)) > 0) { await requestStream.WriteAsync(buffer, 0, bytesRead); bytesSent += bytesRead; progress?.Report((int)(bytesSent * 100 / totalBytes)); } } using (var response = (FtpWebResponse)await request.GetResponseAsync()) Console.WriteLine($"上传成功: {remoteFilePath}"); } private async Task CreateDirectoryAsync(string directoryPath) { var directories = directoryPath.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries); var currentPath = string.Empty; foreach (var dir in directories) { currentPath = $"{currentPath}/{dir}"; var request = (FtpWebRequest)WebRequest.Create($"{_host}{currentPath}"); request.Method = WebRequestMethods.Ftp.MakeDirectory; request.Credentials = new NetworkCredential(_username, _password); request.UsePassive = true; request.KeepAlive = false; if (_useFtps) { request.EnableSsl = true; ServicePointManager.ServerCertificateValidationCallback = ValidateServerCertificate; } try { using (var response = (FtpWebResponse)await request.GetResponseAsync()) Console.WriteLine($"创建目录 {currentPath}"); } catch (WebException ex) { if (((FtpWebResponse)ex.Response)?.StatusCode is FtpStatusCode.ActionNotTakenFileUnavailable or FtpStatusCode.FileActionNotTaken) continue; throw; } } } private bool ValidateServerCertificate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { if (sslPolicyErrors == SslPolicyErrors.None) return true; if (!string.IsNullOrEmpty(_trustedThumbprint) && certificate.GetCertHashString().Replace(" ", "").ToUpper() == _trustedThumbprint.ToUpper()) return true; if (chain != null) { chain.ChainPolicy.RevocationMode = X509RevocationMode.Online; if (chain.Build(new X509Certificate2(certificate)) && chain.ChainStatus.Length == 0) return true; } return false; } } }

优化后的主程序：csharp

using System; using System.Threading; using System.Threading.Tasks; using System.Windows.Forms; namespace FTP客户端Demo { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private async void btnUpload_Click(object sender, EventArgs e) { string ftpserver = tbftpServer.Text; string remoteFilePath = tbfilePath.Text; string username = tbusername.Text; string password = tbpassword.Text; string localFilePath = txtLocalFilePath.Text; string trustedThumbprint = tbTrustedThumbprint.Text; if (string.IsNullOrEmpty(ftpserver) || string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password) || string.IsNullOrEmpty(localFilePath) || string.IsNullOrEmpty(remoteFilePath)) { MessageBox.Show("请填写所有必填字段！", "错误"); return; } try { var ftpClient = new FtpClient(ftpserver, username, password, true, trustedThumbprint); btnUpload.Enabled = false; label5.Text = "0 / 100"; int maxConcurrentUploads = 5, completedCount = 0; var tasks = new Task[maxConcurrentUploads]; for (int i = 0; i < 100; i++) { var remoteFilePathNew = $"{remoteFilePath}/{i}.bmp"; var progress = new Progress<int>(_ => Invoke((Action)(() => label5.Text = $"{completedCount} / 100"))); int taskIndex = Task.WaitAny(tasks); if (taskIndex >= 0) tasks[taskIndex] = null; tasks[taskIndex] = Task.Run(async () => { try { await ftpClient.UploadFileAsync(localFilePath, remoteFilePathNew, true, progress); Interlocked.Increment(ref completedCount); } catch (Exception ex) { Invoke((Action)(() => MessageBox.Show($"上传 {remoteFilePathNew} 失败: {ex.Message}", "错误"))); } }); if (i < maxConcurrentUploads) await Task.Delay(100); } await Task.WhenAll(tasks.Where(t => t != null)); MessageBox.Show("上传完成！", "成功"); } catch (Exception ex) { MessageBox.Show($"上传失败: {ex.Message}", "错误"); } finally { btnUpload.Enabled = true; } } } }

使用：

• 控件：tbftpServer, tbfilePath, tbusername, tbpassword, txtLocalFilePath, tbTrustedThumbprint (TextBox), label5 (Label), btnUpload (Button)。
• 运行：输入 FTP 信息，点击上传，label5 显示进度（如 “50 / 100”）。
• 要求：.NET Framework 4.8 或 .NET 6+，FTPS 服务器，证书指纹（测试可选）。

建议：

• 添加重试机制。
• 用 ProgressBar 替换 label5。
• 集成 Serilog 日志。
• 考虑 SFTP（SSH.NET）以提升安全性。

如需 SFTP 或其他优化，请告知！