ftp上传下载

app.config中

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="HostName" value="172.31.68.95"/>
  </appSettings>
</configuration>

在program.cs中调用

 static void Main(string[] args)
        {
            //上传：上传的路径、要上传的文件路径，上传到的地址，ftp用户名、密码
            string hostName = ConfigurationManager.AppSettings["HostName"].ToString();
            System.IO.FileInfo fi = new System.IO.FileInfo("D://my//upload.txt");//文件必须存在，若不存在要报错
            FileOperator.UploadFile(fi, "/aa", hostName, "", "");
        }

写一个类。

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Xml.Linq;

using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Net;

/// <summary>
/// Summary description for FtpUpandDwonFile
/// </summary>
public class FtpUtility
{
    public FtpUtility()
    {
        //
        // TODO: Add constructor logic here
        //
    }

    private static FtpWebRequest GetRequest(string URI, string username, string password)
    {
        FtpWebRequest result = (FtpWebRequest)FtpWebRequest.Create(URI);
        result.Credentials = new System.Net.NetworkCredential(username, password);
        result.KeepAlive = false;
        return result;
    }

    /// <summary>
    /// 上传文件
    /// </summary>
    /// <param name="fileinfo">需要上传的文件</param>
    /// <param name="targetDir">目标路径</param>
    /// <param name="hostname">ftp地址</param>
    /// <param name="username">ftp用户名</param>
    /// <param name="password">ftp密码</param>
    public static void UploadFile(FileInfo fileinfo, string targetDir, string hostname, string username, string password)
    {
        //1. check target
        string target;
        if (targetDir.Trim() == "")
        {
            return;
        }
        target = Guid.NewGuid().ToString();  //使用临时文件名

        string URI = "FTP://" + hostname + "/" + targetDir + "/" + target + ".tmp";
        ///WebClient webcl = new WebClient();

        System.Net.FtpWebRequest ftp = GetRequest(URI, username, password);

        //设置FTP命令
        ftp.Method = System.Net.WebRequestMethods.Ftp.UploadFile;
        ftp.UseBinary = true;
        ftp.UsePassive = true;

        //告诉ftp文件大小
        ftp.ContentLength = fileinfo.Length;

        const int BufferSize = 2048;
        byte[] content = new byte[BufferSize - 1 + 1];
        int dataRead;

        //上传文件内容
        using (FileStream fs = fileinfo.OpenRead())
        {
            try
            {
                using (Stream rs = ftp.GetRequestStream())
                {
                    do
                    {
                        dataRead = fs.Read(content, 0, BufferSize);
                        rs.Write(content, 0, dataRead);
                    } while (!(dataRead < BufferSize));
                    rs.Close();
                }

            }
            catch (Exception ex) { }
            finally
            {
                fs.Close();
            }

        }

        ftp = null;

        //设置FTP命令
        ftp = GetRequest(URI, username, password);
        ftp.Method = System.Net.WebRequestMethods.Ftp.Rename; //改名
        ftp.RenameTo = fileinfo.Name;
        try
        {
            ftp.GetResponse();
        }
        catch (Exception ex)
        {
            ftp = GetRequest(URI, username, password);
            ftp.Method = System.Net.WebRequestMethods.Ftp.DeleteFile; //删除
            ftp.GetResponse();
            throw ex;
        }
        finally
        {

            //fileinfo.Delete();
        }

        // 可以记录一个日志  "上传" + fileinfo.FullName + "上传到" + "FTP://" + hostname + "/" + targetDir + "/" + fileinfo.Name + "成功." );
        ftp = null;
    }

    /// <summary>
    /// 下载文件
    /// </summary>
    /// <param name="localDir">本地路径</param>
    /// <param name="FtpDir">ftp路径</param>
    /// <param name="FtpFile">ftp文件名</param>
    /// <param name="hostname">ftp地址</param>
    /// <param name="username">ftp用户名</param>
    /// <param name="password">ftp密码</param>
    public static void DownloadFile(string localDir, string FtpDir, string FtpFile, string hostname, string username, string password)
    {

        string URI = "FTP://" + hostname + "/" + FtpDir + "/" + FtpFile;
        string tmpname = Guid.NewGuid().ToString();
        string localfile = localDir + @"\" + tmpname;

        System.Net.FtpWebRequest ftp = GetRequest(URI, username, password);
        ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile;
        ftp.UseBinary = true;
        ftp.UsePassive = false;

        using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                //loop to read & write to file
                using (FileStream fs = new FileStream(localfile, FileMode.CreateNew))
                {
                    try
                    {
                        byte[] buffer = new byte[2048];
                        int read = 0;
                        do
                        {
                            read = responseStream.Read(buffer, 0, buffer.Length);
                            fs.Write(buffer, 0, read);
                        } while (!(read == 0));
                        responseStream.Close();
                        fs.Flush();
                        fs.Close();
                    }
                    catch (Exception)
                    {
                        //catch error and delete file only partially downloaded
                        fs.Close();
                        //delete target file as it's incomplete
                        File.Delete(localfile);
                        throw;
                    }
                }

                responseStream.Close();
            }

            response.Close();
        }

        try
        {
            File.Delete(localDir + @"\" + FtpFile);
            File.Move(localfile, localDir + @"\" + FtpFile);

            ftp = null;
            ftp = GetRequest(URI, username, password);
            ftp.Method = System.Net.WebRequestMethods.Ftp.DeleteFile;
            ftp.GetResponse();

        }
        catch (Exception ex)
        {
            File.Delete(localfile);
            throw ex;
        }

        // 记录日志 "从" + URI.ToString() + "下载到" + localDir + @"\" + FtpFile + "成功." );
        ftp = null;

    }

    /// <summary>
    /// 搜索远程文件
    /// </summary>
    /// <param name="targetDir"></param>
    /// <param name="hostname"></param>
    /// <param name="username"></param>
    /// <param name="password"></param>
    /// <param name="SearchPattern"></param>
    /// <returns></returns>
    public static List<string> ListDirectory(string targetDir, string hostname, string username, string password, string SearchPattern)
    {
        List<string> result = new List<string>();
        try
        {
            string URI = "FTP://" + hostname + "/" + targetDir + "/" + SearchPattern;

            System.Net.FtpWebRequest ftp = GetRequest(URI, username, password);
            ftp.Method = System.Net.WebRequestMethods.Ftp.ListDirectory;
            ftp.UsePassive = true;
            ftp.UseBinary = true;

            string str = GetStringResponse(ftp);
            str = str.Replace("\r\n", "\r").TrimEnd('\r');
            str = str.Replace("\n", "\r");
            if (str != string.Empty)
                result.AddRange(str.Split('\r'));

            return result;
        }
        catch { }
        return null;
    }

    private static 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.Default))
                {
                    result = sr.ReadToEnd();
                    sr.Close();
                }

                datastream.Close();
            }

            response.Close();
        }

        return result;
    }

}