C# 实现FTP客户端
本文是利用C# 实现FTP客户端的小例子，主要实现上传，下载，删除等功能，以供学习分享使用。
思路：
- 通过读取FTP站点的目录信息，列出对应的文件及文件夹。
- 双击目录，则显示子目录，如果是文件，则点击右键，进行下载和删除操作。
- 通过读取本地电脑的目录，以树状结构展示，选择本地文件，右键进行上传操作。
涉及知识点：
- FtpWebRequest【实现文件传输协议 (FTP) 客户端】 / FtpWebResponse【封装文件传输协议 (FTP) 服务器对请求的响应】Ftp的操作主要集中在两个类中。
- FlowLayoutPanel 【流布局面板】表示一个沿水平或垂直方向动态排放其内容的面板。
- ContextMenuStrip 【快捷菜单】主要用于右键菜单。
- 资源文件：Resources 用于存放图片及其他资源。
效果图如下
左边：双击文件夹进入子目录，点击工具栏按钮‘上级目录’返回。文件点击右键进行操作。
右边：文件夹则点击前面+号展开。文件则点击右键进行上传。
核心代码如下
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace FtpClient
{
public class FtpHelper
{
#region 属性与构造函数
/// <summary>
/// IP地址
/// </summary>
public string IpAddr { get; set; }
/// <summary>
/// 相对路径
/// </summary>
public string RelatePath { get; set; }
/// <summary>
/// 端口号
/// </summary>
public string Port { get; set; }
/// <summary>
/// 用户名
/// </summary>
public string UserName { get; set; }
/// <summary>
/// 密码
/// </summary>
public string Password { get; set; }
public FtpHelper() {
}
public FtpHelper(string ipAddr, string port, string userName, string password) {
this.IpAddr = ipAddr;
this.Port = port;
this.UserName = userName;
this.Password = password;
}
#endregion
#region 方法
/// <summary>
/// 下载文件
/// </summary>
/// <param name="filePath"></param>
/// <param name="isOk"></param>
public void DownLoad(string filePath, out bool isOk) {
string method = WebRequestMethods.Ftp.DownloadFile;
var statusCode = FtpStatusCode.DataAlreadyOpen;
FtpWebResponse response = callFtp(method);
ReadByBytes(filePath, response, statusCode, out isOk);
}
public void UpLoad(string file,out bool isOk)
{
isOk = false;
FileInfo fi = new FileInfo(file);
FileStream fs = fi.OpenRead();
long length = fs.Length;
string uri = string.Format("ftp://{0}:{1}{2}", this.IpAddr, this.Port, this.RelatePath);
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(uri);
request.Credentials = new NetworkCredential(UserName, Password);
request.Method = WebRequestMethods.Ftp.UploadFile;
request.UseBinary = true;
request.ContentLength = length;
request.Timeout = 10 * 1000;
try
{
Stream stream = request.GetRequestStream();
int BufferLength = 2048; //2K
byte[] b = new byte[BufferLength];
int i;
while ((i = fs.Read(b, 0, BufferLength)) > 0)
{
stream.Write(b, 0, i);
}
stream.Close();
stream.Dispose();
isOk = true;
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally {
if (request != null)
{
request.Abort();
request = null;
}
}
}
/// <summary>
/// 删除文件
/// </summary>
/// <param name="isOk"></param>
/// <returns></returns>
public string[] DeleteFile(out bool isOk) {
string method = WebRequestMethods.Ftp.DeleteFile;
var statusCode = FtpStatusCode.FileActionOK;
FtpWebResponse response = callFtp(method);
return ReadByLine(response, statusCode, out isOk);
}
/// <summary>
/// 展示目录
/// </summary>
public string[] ListDirectory(out bool isOk)
{
string method = WebRequestMethods.Ftp.ListDirectoryDetails;
var statusCode = FtpStatusCode.DataAlreadyOpen;
FtpWebResponse response= callFtp(method);
return ReadByLine(response, statusCode, out isOk);
}
/// <summary>
/// 设置上级目录
/// </summary>
public void SetPrePath()
{
string relatePath = this.RelatePath;
if (string.IsNullOrEmpty(relatePath) || relatePath.LastIndexOf("/") == 0 )
{
relatePath = "";
}
else {
relatePath = relatePath.Substring(0, relatePath.LastIndexOf("/"));
}
this.RelatePath = relatePath;
}
#endregion
#region 私有方法
/// <summary>
/// 调用Ftp,将命令发往Ftp并返回信息
/// </summary>
/// <param name="method">要发往Ftp的命令</param>
/// <returns></returns>
private FtpWebResponse callFtp(string method)
{
string uri = string.Format("ftp://{0}:{1}{2}", this.IpAddr, this.Port, this.RelatePath);
FtpWebRequest request; request = (FtpWebRequest)FtpWebRequest.Create(uri);
request.UseBinary = true;
request.UsePassive = true;
request.Credentials = new NetworkCredential(UserName, Password);
request.KeepAlive = false;
request.Method = method;
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
return response;
}
/// <summary>
/// 按行读取
/// </summary>
/// <param name="response"></param>
/// <param name="statusCode"></param>
/// <param name="isOk"></param>
/// <returns></returns>
private string[] ReadByLine(FtpWebResponse response, FtpStatusCode statusCode,out bool isOk) {
List<string> lstAccpet = new List<string>();
int i = 0;
while (true)
{
if (response.StatusCode == statusCode)
{
using (StreamReader sr = new StreamReader(response.GetResponseStream()))
{
string line = sr.ReadLine();
while (!string.IsNullOrEmpty(line))
{
lstAccpet.Add(line);
line = sr.ReadLine();
}
}
isOk = true;
break;
}
i++;
if (i > 10)
{
isOk = false;
break;
}
Thread.Sleep(200);
}
response.Close();
return lstAccpet.ToArray();
}
private void ReadByBytes(string filePath,FtpWebResponse response, FtpStatusCode statusCode, out bool isOk)
{
isOk = false;
int i = 0;
while (true)
{
if (response.StatusCode == statusCode)
{
long length = response.ContentLength;
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
using (FileStream outputStream = new FileStream(filePath, FileMode.Create))
{
using (Stream ftpStream = response.GetResponseStream())
{
readCount = ftpStream.Read(buffer, 0, bufferSize);
while (readCount > 0)
{
outputStream.Write(buffer, 0, readCount);
readCount = ftpStream.Read(buffer, 0, bufferSize);
}
}
}
break;
}
i++;
if (i > 10)
{
isOk = false;
break;
}
Thread.Sleep(200);
}
response.Close();
}
#endregion
}
/// <summary>
/// Ftp内容类型枚举
/// </summary>
public enum FtpContentType
{
undefined = 0,
file = 1,
folder = 2
}
}FTP服务端和客户端示意图
---------------------------------------------------------------------------------------------------
版权声明：本文为开发框架文库发布内容,转载请附上原文出处连接
newdoc C/S框架网
