C# FTP的使用

直接上代码如下：

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            FtpHelper ftpHelper = new FtpHelper("xxxxx", "","Administrator","1qaz@qwer");
            string[] datas = ftpHelper.GetAllList(null);
            Console.WriteLine(JsonConvert.SerializeObject(datas));
            Console.ReadLine();
        } 
    }


    public class FtpHelper
    {
        string ftpServerIP;
        string ftpRemotePath;
        string ftpUserID;
        string ftpPassword;
        string ftpURI;

        /// <summary>
        /// 连接FTP
        /// </summary>
        /// <param name="FtpServerIP">FTP连接地址</param>
        /// <param name="FtpRemotePath">指定FTP连接成功后的当前目录, 如果不指定即默认为根目录</param>
        /// <param name="FtpUserID">用户名</param>
        /// <param name="FtpPassword">密码</param>
        public FtpHelper(string FtpServerIP, string FtpRemotePath, string FtpUserID, string FtpPassword)
        {
            ftpServerIP = FtpServerIP;
            ftpRemotePath = FtpRemotePath;
            ftpUserID = FtpUserID;
            ftpPassword = FtpPassword;
            if (string.IsNullOrEmpty(ftpRemotePath))
            {
                ftpURI = "ftp://" + ftpServerIP + "/";
            }
            else
            {
                ftpURI = "ftp://" + ftpServerIP + "/" + ftpRemotePath + "/";
            }
            
        }


        /// <summary>
        /// 下载
        /// </summary>
        /// <param name="filePath">下载保存的文件夹路径</param>
        /// <param name="fileName">文件名称</param>
        public bool Download(string filePath, string fileName)
        {
            try
            {
                FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);
                FtpWebRequest reqFTP;
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
                reqFTP.Cred