如何使用FtpWebRequest对ftp服务器上面的目录进行改名（注意是目录不是文件！）

比如我的ftp服务器针对user用户建立了一个目录（名字为0）
那么我在客户端如何对其改名(改为1）了？
请大家帮忙提供下正确的代码（最好自己先测试通过！）
下面是我的部分代码
            URI = @"ftp://"+服务器ip+"/0";
            System.Net.FtpWebRequest ftp = GetRequest(URI);
            //Set request to delete
            ftp.Method = System.Net.WebRequestMethods.Ftp.Rename;
            ftp.RenameTo = "/1";
            try
            {
                //get response but ignore it
                string str = GetStringResponse(ftp);///运行到这里会报错！！！
            }
            catch (Exception)
            {
                return false;
            }

 //Get the basic FtpWebRequest object with the
        //common settings and security
        private FtpWebRequest GetRequest(string URI)
        {
            URI = @"ftp://" + URI;
          
            FtpWebRequest result = (FtpWebRequest)FtpWebRequest.Create(URI);
       
            result.Credentials = GetCredentials();
         
            result.EnableSsl = false;
        
            result.KeepAlive = false;
            // support for passive connections
            result.UsePassive = true;
            return result;
        }
       
        private string GetStringResponse(FtpWebRequest ftp)
        {
            //Get the result, streaming to a string
            string result = "";
            using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())
            {
                long size = response.ContentLength;
                using (Stream datastream = response.GetResponseStream())
                {
                    using (StreamReader sr = new StreamReader(datastream, System.Text.Encoding.UTF8))
                    {
                        result = sr.ReadToEnd();
                        sr.Close();
                    }

                    datastream.Close();
                }

                response.Close();
            }

            return result;
        }