C# 检查 FTP 目录是否存在

Question

我有这个 FTP 方法来检查目录是否存在。它在开始时工作正常，但现在，即使目录不存在，它仍然返回 true。我尝试了很多东西，并设置了断点来查看我可以使用响应对象的哪些属性来确定目录是否存在。我还搜索了互联网，解决方案似乎对我不起作用。这是我的 FTP 方法。

public bool directoryExists(string directory)
            {
                /* Create an FTP Request */
                ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + directory);
                /* Log in to the FTP Server with the User Name and Password Provided */
                ftpRequest.Credentials = new NetworkCredential(user, pass);
                /* Specify the Type of FTP Request */
                ftpRequest.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
                try
                {
                    using (ftpRequest.GetResponse())
                    {
                        return true;
                    }
                    //var response = ftpRequest.GetResponse();
                    //if (response != null)
                    //    return true;
                    //else return false;
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.ToString());
                    return false;
                }

                /* Resource Cleanup */
                finally
                {
                    ftpRequest = null;
                }
            }

这是调用它的方法，即使目录不存在也返回true：

private string getDirectory(ref FtpClass ftp, string internalID)
        {
            string remoteSubPathDel = internalID + "\\trunk\\prod\\xml\\delete";
            string remoteSubPathUpdate = internalID + "\\trunk\\prod\\xml\\update";
            string remoteSubPathNew = internalID + "\\trunk\\prod\\xml\\new";
            if (ftp.directoryExists(remoteSubPathDel))
                return remoteSubPathDel;
            else if (ftp.directoryExists(remoteSubPathUpdate))
                return remoteSubPathUpdate;
            else if (ftp.directoryExists(remoteSubPathNew))
                return remoteSubPathNew;
            else
                return String.Empty;
        }

希望有人可以提供帮助。谢谢！ :)

Answer 1

In 2021 这适用于我们的 Linux 和 Windows live 从 ftp 服务器读取的框（在 Windows 和 Linux 上）

注意

• Windows ftp 上的主文件夹是 web
• Linux ftp 上的主文件夹是 public_html

TL;DR;

• 底线：URL 需要以 / 结尾

有效：

ftp://ftp.yourdomain.com.br/public_html/
ftp://ftp.yourdomain.com.br//public_html/
ftp://ftp.yourdomain.com.br/web/
ftp://ftp.yourdomain.com.br//web/

它不起作用：

ftp://ftp.yourdomain.com.br/public_html
ftp://ftp.yourdomain.com.br//public_html
ftp://ftp.yourdomain.com.br/web
ftp://ftp.yourdomain.com.br//web

用法： //验证目录public_html是否存在

var url = "/public_html/";
var result = FtpUtil.DoesDirectoryExists(url,  "ftp://ftp.yourdomain.com.br", "ftp user here", "ftp password here");

---

static bool DoesDirectoryExists(string directory, string ftpHost, string ftpUser, string ftpPassword) {
                    FtpWebRequest ftpRequest = null;
                    try {
                            ftpRequest = (FtpWebRequest)WebRequest.Create(new Uri("ftp://" + ftpHost + directory));
                            ftpRequest.Credentials = new NetworkCredential(ftpUser, string ftpPassword);
                            ftpRequest.UseBinary = true;// optional
                            ftpRequest.KeepAlive = false;// optional
                            ftpRequest.UsePassive = true;// optional
                            ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory;
        
                            using (FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse()) {
                                return true;//directory found
                            }
                    }
                    catch (WebException ex) {
                            if (ex.Response != null) {
                                FtpWebResponse response = (FtpWebResponse)ex.Response;
                                if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
                                    return false;// directory not found.  
                            }
                            return false; // directory not found.
                    }
                    finally {
                        ftpRequest = null;
                    }
        }

Answer 2

我解决了这个问题。不是最好看，但很管用。

也许这可以帮助其他与我有同样问题的人。

public bool directoryExists2(string directory, string mainDirectory)
        {
            try
            {
                var list = this.GetFileList(mainDirectory);
                if (list.Contains(directory))
                    return true;
                else
                    return false;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return false;
            }
        }

编辑：我包含了 GetFileList 方法以响应 Ray Chang 的评论

public string[] GetFileList(string path)
        {
            var ftpPath = host + "/" + path;
            var ftpUser = user;
            var ftpPass = pass;
            var result = new StringBuilder();
            try
            {
                var strLink = ftpPath;
                var reqFtp = (FtpWebRequest)WebRequest.Create(new Uri(strLink));
                reqFtp.UseBinary = true;
                reqFtp.Credentials = new NetworkCredential(ftpUser, ftpPass);
                reqFtp.Method = WebRequestMethods.Ftp.ListDirectory;
                reqFtp.Proxy = null;
                reqFtp.KeepAlive = false;
                reqFtp.UsePassive = true;
                using (var response = reqFtp.GetResponse())
                {
                    using (var reader = new StreamReader(response.GetResponseStream()))
                    {
                        var line = reader.ReadLine();
                        while (line != null)
                        {
                            result.Append(line);
                            result.Append("\n");
                            line = reader.ReadLine();
                        }
                        result.Remove(result.ToString().LastIndexOf('\n'), 1);
                    }
                }
                return result.ToString().Split('\n');
            }
            catch (Exception ex)
            {
                Console.WriteLine("FTP ERROR: ", ex.Message);
                return null;
            }

            finally
            {
                ftpRequest = null;
            }
        }

Answer 3

试试这个：

public bool directoryExists(string directory)
{
    /* Create an FTP Request */
    ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + directory);
    /* Log in to the FTP Server with the User Name and Password Provided */
    ftpRequest.Credentials = new NetworkCredential(user, pass);
    /* Specify the Type of FTP Request */
    ftpRequest.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
    try
    {
        using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
        {
            return true;
        }
    }
    catch (Exception ex)
    {
        return false;
    }

            /* Resource Cleanup */
    finally
    {
        ftpRequest = null;
    }
}

注意这一行using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())