using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;



namespace SimpleFtp

{

    internal class WinAPI

    {

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]

        public class WIN32_FIND_DATA

        {

            public UInt32 dwFileAttributes = 0;

            public FILETIME ftCreationTime;

            public FILETIME ftLastAccessTime;

            public FILETIME ftLastWriteTime;

            public UInt32 nFileSizeHigh = 0;

            public UInt32 nFileSizeLow = 0;

            public UInt32 dwReserved0 = 0;

            public UInt32 dwReserved1 = 0;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]

            public string cFileName = null;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]

            public string cAlternateFileName = null;

        };

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]

        public class FILETIME

        {

            public int dwLowDateTime = 0;

            public int dwHighDateTime = 0;

        };



        public const int INTERNET_FLAG_PASSIVE = 0x8000000; //被动模式

        public const int INTERNET_FLAG_PORT = 0x0;          //主动模式



        public const uint INTERNET_FLAG_RELOAD = 0x80000000;         //

        public const uint INTERNET_FLAG_KEEP_CONNECTION = 0x400000;  //

        public const uint INTERNET_FLAG_MULTIPART = 0x200000;        //



        public const int INTERNET_OPEN_TYPE_PRECONFIG = 0;

        public const int INTERNET_OPEN_TYPE_DIRECT = 1;

        public const int INTERNET_OPEN_TYPE_PROXY = 3;



        public const int INTERNET_SERVICE_FTP = 1;

        public const int INTERNET_SERVICE_GOPHER = 2;

        public const int INTERNET_SERVICE_HTTP = 3;



        public const uint FTP_TRANSFER_TYPE_ASCII = 0x1;

        public const uint FTP_TRANSFER_TYPE_BINARY = 0x2;



        public const int FILE_ATTRIBUTE_READONLY = 0x1;

        public const int FILE_ATTRIBUTE_HIDDEN = 0x2;

        public const int FILE_ATTRIBUTE_SYSTEM = 0x4;

        public const int FILE_ATTRIBUTE_DIRECTORY = 0x10;

        public const int FILE_ATTRIBUTE_ARCHIVE = 0x20;

        public const int FILE_ATTRIBUTE_NORMAL = 0x80;

        public const int FILE_ATTRIBUTE_TEMPORARY = 0x100;

        public const int FILE_ATTRIBUTE_COMPRESSED = 0x800;

        // 连接和初始化

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

        public static extern void SetLastError(int dwErrCode);



        // 连接和初始化

        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern IntPtr InternetOpen(string strAppName, int nAccessType, string strProxy, string strProxyBypass, int nFlags);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern IntPtr InternetConnect(IntPtr hInet, string strServer, int nPort, string strUser, string strPassword

            , int nService, int nFlags, int nContext);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool InternetCloseHandle(IntPtr hSession);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool InternetGetConnectedState(ref int ulFlags, int ulReserved);



        // Ftp文件操作命令

        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern IntPtr FtpFindFirstFile(IntPtr hSession, string strPath, [In, Out] WIN32_FIND_DATA dirData, int nFlags, int nContext);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool InternetFindNextFile(IntPtr hFind, [In, Out] WIN32_FIND_DATA dirData);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpGetFile(IntPtr hFtpSession, string lpszRemoteFile, string lpszNewFile

            , bool fFailIfExists, int dwFlagsAndAttributes, uint dwFlags, int dwContext);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpPutFile(IntPtr hFtpSession, string lpszLocalFile, string lpszRemoteFile

            , uint dwFlags, int dwContext);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpDeleteFile(IntPtr hFtpSession, string lpszFileName);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpRenameFile(IntPtr hFtpSession, string lpszExisting, string lpszNew);



        // Ftp目录操作命令

        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpGetCurrentDirectory(IntPtr hFtpSession, [In, Out] string lpszCurrentDirectory, ref int lpdwCurrentDirectory);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpSetCurrentDirectory(IntPtr hFtpSession, string lpszCurrentDirectory);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpCreateDirectory(IntPtr hFtpSession, string lpszDirectory);



        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]

        public static extern bool FtpRemoveDirectory(IntPtr hFtpSession, string lpszDirectory);



    }

}

using System;

using System.Collections.Generic;

using System.Text;

using System.Net;

using System.IO;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.ComponentModel;



namespace SimpleFtp

{

    internal class FtpAccess

    {

        private string m_szIP = null;

        private int m_nPort = -1;

        private string m_szUserName = null;

        private string m_szPassword = null;



        private IntPtr m_hInternet = IntPtr.Zero;

        private IntPtr m_hConnect = IntPtr.Zero;



        /// <summary>

        /// 获取或设置FTP的访问IP地址

        /// </summary>

        public string IP

        {

            get

            {

                return this.m_szIP;

            }

            set

            {

                this.m_szIP = value;

            }

        }

        /// <summary>

        /// 获取或设置FTP的访问端口号

        /// </summary>

        public int Port

        {

            get

            {

                return this.m_nPort;

            }

            set

            {

                this.m_nPort = value;

            }

        }

        /// <summary>

        /// 获取或设置FTP的访问用户名称

        /// </summary>

        public string UserName

        {

            get

            {

                return this.m_szUserName;

            }

            set

            {

                this.m_szUserName = value;

            }

        }

        /// <summary>

        /// 获取或设置FTP的访问用户密码

        /// </summary>

        public string Password

        {

            get

            {

                return this.m_szPassword;

            }

            set

            {

                this.m_szPassword = value;

            }

        }



        /// <summary>

        /// 连接到FTP指定的路径

        /// </summary>

        /// <param name="path">路径</param>

        public bool Connect()

        {

            this.InitWinAPI();

            if (this.m_hConnect != IntPtr.Zero)

            {

                if (WinAPI.FtpSetCurrentDirectory(this.m_hConnect, "/"))

                    return true;

            }

            this.CloseConnection();



            if (this.m_szIP == null || this.m_szUserName == null || this.m_szPassword == null)

            {

                //CommonDef.SetLastError("FTP站点连接失败!FTP访问参数未设置");

                return false;

            }



            this.m_hInternet = WinAPI.InternetOpen("ftp", WinAPI.INTERNET_OPEN_TYPE_PRECONFIG, null, null, 0);

            if (this.m_hInternet == null || this.m_hInternet == IntPtr.Zero)

            {

                //CommonDef.SetLastError("FTP站点连接失败!" + this.GetWin32Error());

                return false;

            }



            this.m_hConnect = WinAPI.InternetConnect(this.m_hInternet, this.IP, this.Port, this.UserName, this.Password

                , WinAPI.INTERNET_SERVICE_FTP, WinAPI.INTERNET_FLAG_PASSIVE, 0);

            if (this.m_hConnect == null || this.m_hConnect == IntPtr.Zero)

            {

                //CommonDef.SetLastError("FTP站点连接失败!" + this.GetWin32Error());

                return false;

            }



            if (!WinAPI.FtpSetCurrentDirectory(this.m_hConnect, "/"))

            {

                //CommonDef.SetLastError("FTP站点连接失败!" + this.GetWin32Error());

                return false;

            }

            return true;

        }

        /// <summary>

        /// 关闭FTP连接

        /// </summary>

        public void CloseConnection()

        {

            if (this.m_hConnect != IntPtr.Zero)

            {

                WinAPI.InternetCloseHandle(this.m_hConnect);

                this.m_hConnect = IntPtr.Zero;

            }

            if (this.m_hInternet != IntPtr.Zero)

            {

                WinAPI.InternetCloseHandle(this.m_hInternet);

                this.m_hInternet = IntPtr.Zero;

            }

        }

        /// <summary>

        /// 判断文件或文件夹是否存在

        /// </summary>

        /// <param name="path">文件或文件夹路径</param>

        /// <param name="bIsFolder">资源是否是文件夹</param>

        /// <returns>true:资源存在;false:资源不存在</returns>

        public bool ResExists(string szResPath, bool bIsFolder)

        {

            szResPath = szResPath.Trim();

            if (szResPath == "/" || szResPath == "")

                return true;



            if (!this.Connect())

                return false;



            this.InitWinAPI();

            //if (bIsFolder)

            //{

            if (!WinAPI.FtpSetCurrentDirectory(this.m_hConnect, szResPath))

            {

                return false;

            }

            if (!WinAPI.FtpSetCurrentDirectory(this.m_hConnect, "/"))

            {

                return false;

            }

            return true;

            //}

            //else

            //{

            //    WinAPI.WIN32_FIND_DATA stFileInfo = new WinAPI.WIN32_FIND_DATA();

            //    IntPtr hFile = WinAPI.FtpFindFirstFile(this.m_hConnect, szResPath, stFileInfo, 0, 0);

            //    if (hFile == null || hFile == IntPtr.Zero)

            //    {

            //        return false;

            //    }

            //    WinAPI.InternetCloseHandle(hFile);

            //    return true;

            //}

        }



        /// <summary>

        /// 删除一个本地文件

        /// </summary>

        /// <param name="szFileName">本地文件</param>

        /// <param name="bRaiseException">是否抛出异常</param>

        /// <returns>bool</returns>

        private bool DeleteFile(string szFileName, bool bRaiseException)

        {

            if (!File.Exists(szFileName))

                return true;

            try

            {

                File.Delete(szFileName);

                return true;

            }

            catch (Exception ex)

            {

                if (bRaiseException)

                    throw ex;

                return false;

            }

        }



        private bool RenameFile(string szFileName, string szNewName, bool bRaiseException)

        {

            if (!File.Exists(szFileName))

                return true;

            try

            {

                File.Move(szFileName, szNewName);

                return true;

            }

            catch (Exception ex)

            {

                if (bRaiseException)

                    throw ex;

                return false;

            }

        }



        /// <summary>

        /// 上传本地文件到服务器

        /// </summary>

        /// <param name="szLocalFile">本地源文件全路径</param>

        /// <param name="szRemoteFile">目的服务器文件全路径</param>

        /// <returns>true:上传成功;false:上传失败</returns>

        public bool Upload(string szLocalFile, string szRemoteFile)

        {

            FileInfo fileInfo = new FileInfo(szLocalFile);

            if (fileInfo == null || !fileInfo.Exists)

                return false;



            if (!File.Exists(szLocalFile))

            {

                //CommonDef.SetLastError(string.Format("文件{0}上传失败!本地文件不存在!", szLocalFile));

                return false;

            }



            //if (this.ResExists(szRemoteFile, false))

            //{

            //    string szErrorInfo = string.Format("文件{0}上传到{1}失败!远程文件已经存在!"

            //        , szLocalFile, szRemoteFile);

            //CommonDef.SetLastError(szErrorInfo);

            //    return false;

            //}



            this.InitWinAPI();

            if (!WinAPI.FtpPutFile(this.m_hConnect, szLocalFile, szRemoteFile, WinAPI.FTP_TRANSFER_TYPE_BINARY | WinAPI.INTERNET_FLAG_RELOAD, 0))

            {

                string szErrorInfo = string.Format("文件{0}上传到文件{1}失败!", szLocalFile, szRemoteFile);

                //CommonDef.SetLastError(szErrorInfo + this.GetWin32Error());

                return false;

            }

            return true;

        }

        /// <summary>

        /// 下载指定的FTP路径上的文件

        /// </summary>

        /// <param name="szRemoteFile">远程文件</param>

        /// <param name="szLocalFile">保存本地文件名</param>

        /// <returns>true:下载成功;false:下载失败</returns>

        public bool Download(string szRemoteFile, string szLocalFile)

        {

            try

            {

                this.RenameFile(szLocalFile, szLocalFile + ".tmp", true);

            }

            catch (Exception ex)

            {

                string szErrorInfo = string.Format("文件{0}下载到文件{1}失败!无法重命名本地已存在文件"

                    , szRemoteFile, szLocalFile);

                //CommonDef.SetLastError(szErrorInfo + ex.Message);

                return false;

            }



            //if (!this.ResExists(szRemoteFile, false))

            //{

            //CommonDef.SetLastError(string.Format("文件{0}下载失败!远程文件不存在!", szRemoteFile));

            //    return false;

            //}



            this.InitWinAPI();

            //INTERNET_FLAG_RELOAD..清空缓存...

            if (!WinAPI.FtpGetFile(this.m_hConnect, szRemoteFile, szLocalFile, false, 0, WinAPI.FTP_TRANSFER_TYPE_BINARY | WinAPI.INTERNET_FLAG_RELOAD, 0))

            {

                //更改文件名，否则FtpGetFile函数会自动删除本地的文件...

                this.RenameFile(szLocalFile + ".tmp", szLocalFile, false);

                string szError = this.GetWin32Error();

                string szErrorInfo = string.Format("文件{0}下载到文件{1}失败!", szRemoteFile, szLocalFile);

                //CommonDef.SetLastError(szErrorInfo + this.GetWin32Error());

                return false;

            }

            if (!File.Exists(szLocalFile))

            {

                //更改文件名，否则FtpGetFile函数会自动删除本地的文件...

                this.RenameFile(szLocalFile + ".tmp", szLocalFile, false);

                string szErrorInfo = string.Format("文件{0}下载到文件{1}失败!", szRemoteFile, szLocalFile);

                //CommonDef.SetLastError(szErrorInfo);

                return false;

            }

            //删除本地的临时文件...

            this.DeleteFile(szLocalFile + ".tmp", false);

            return true;

        }

   /// <summary>

        /// 创建指定路径上所有缺失的目录

        /// </summary>

        /// <param name="dirPath">目录</param>

        /// <returns>bool</returns>

        public bool CreateDirectory(string szDirPath)

        {

            if (this.ResExists(szDirPath, true))

                return true;



            string[] arrDirName = szDirPath.Split(new char[] { '/' });

            szDirPath = string.Empty;

            for (int index = 0; index < arrDirName.Length; index++)

            {

                string szDirName = arrDirName[index];

                if (szDirName == null || szDirName.Trim() == string.Empty)

                    continue;

                szDirPath += "/" + szDirName;

                if (this.ResExists(szDirPath, true))

                    continue;

                this.InitWinAPI();



                if (!WinAPI.FtpCreateDirectory(this.m_hConnect, szDirPath))

                {

                    string szErrorInfo = string.Format("目录{0}创建失败!", szDirPath);

                    //CommonDef.SetLastError(szErrorInfo + this.GetWin32Error());

                    return false;

                }

            }

            return true;

        }

        /// <summary>

        /// 获取指定目录的文件列表

        /// </summary>

        /// <param name="szDirPath">目录路径</param>

        /// <param name="bFolder">是否为文件夹属性</param>

        /// <param name="lstFilePath">返回的文件列表</param>

        /// <returns>bool</returns>

        public bool GetFileList(string szDirPath, bool bFolder, ref List<string> lstFilePath)

        {

            if (!this.ResExists(szDirPath, true))

            {

                string szErrorInfo = string.Format("列表目录{0}下的文件失败!远程目录不存在", szDirPath);

                //CommonDef.SetLastError(szErrorInfo + this.GetWin32Error());

                return false;

            }

            WinAPI.WIN32_FIND_DATA stFileInfo = new WinAPI.WIN32_FIND_DATA();

            IntPtr hFile = WinAPI.FtpFindFirstFile(this.m_hConnect, szDirPath, stFileInfo, 0, 0);

            if (hFile == IntPtr.Zero)

                return false;



            if (lstFilePath == null)

                lstFilePath = new List<string>();



            // 遍历父目录查找指定的子目录是否存在

            bool bSuccess = true;

            while (bSuccess)

            {

                if (bFolder)

                {

                    if (this.IsDirectory(stFileInfo.dwFileAttributes))

                    {

                        string szChildPath = string.Format("{0}/{1}", szDirPath, stFileInfo.cFileName);

                        lstFilePath.Add(szChildPath);

                    }

                }

                else

                {

                    if (!this.IsDirectory(stFileInfo.dwFileAttributes))

                    {

                        string szChildPath = string.Format("{0}/{1}", szDirPath, stFileInfo.cFileName);

                        lstFilePath.Add(szChildPath);

                    }

                }

                bSuccess = WinAPI.InternetFindNextFile(hFile, stFileInfo);

            }

            WinAPI.InternetCloseHandle(hFile);

            return true;

        }

        /// <summary>

        /// 指定的文件属性是否是文件夹属性

        /// </summary>

        /// <param name="dwFileAttributes">文件属性</param>

        /// <returns>bool</returns>

        private bool IsDirectory(UInt32 dwFileAttributes)

        {

            if ((dwFileAttributes & WinAPI.FILE_ATTRIBUTE_DIRECTORY) == WinAPI.FILE_ATTRIBUTE_DIRECTORY)

                return true;

            else

                return false;

        }



        private void InitWinAPI()

        {

            //CommonDef.SetLastError(null);

            //WinAPI.SetLastError(0);

        }



        private string GetWin32Error()

        {

            //int nErrorCode = Marshal.GetLastWin32Error();

            //if (nErrorCode == 0)

            //    return null;

            //return (new Win32Exception(nErrorCode)).Message;

            return string.Empty;

        }

    }

}

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.IO;





namespace SimpleFtp

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }



        private void btConnect_Click(object sender, EventArgs e)

        {

            FtpAccess ftpp = new FtpAccess();

            ftpp.IP = "192.168.123.161";

            ftpp.Port = 21;

            ftpp.UserName = "zhou";

            ftpp.Password = "";



            if (ftpp.Connect())

            {

                try

                {

                    if (ftpp.Upload("\\DiskOnChip\\asd.jpg", "\\asd.jpg"))

                    {

                        MessageBox.Show("上传成功...");

                        ftpp.CloseConnection();

                        

                    }

                    else

                    {

                        MessageBox.Show("下载文件失败...");

                        ftpp.CloseConnection();

                        return;

                    }

                }

                catch (Exception ex)

                {

                    MessageBox.Show("下载文件失败..."+ex.ToString());

                    ftpp.CloseConnection();

                    return ;

                }

            }

            else

            {

                MessageBox.Show("FTP连接失败...");

            }

            ftpp.CloseConnection();

        }



        private void button1_Click(object sender, EventArgs e)

        {

            

            FtpAccess ftpp = new FtpAccess();

            ftpp.IP = "192.168.123.161";

            ftpp.Port = 21;

            ftpp.UserName = "zhou";

            ftpp.Password = "";

           

              //bool ConnectStates =ftpp.Connect() ;

            if (ftpp.Connect())

            //if(ConnectStates ==true)

            {

                try

                {

                    if (ftpp.Download("\\EmployeeTxt.txt", "\\DiskOnChip\\EmployeeTxt.txt"))

                    {

                        MessageBox.Show("下载文件成功...");

                        ftpp.CloseConnection();

                    }

                    else

                    {

                        MessageBox.Show("下载文件失败...");

                        ftpp.CloseConnection();

                        return;

                    }

                }

                catch(Exception ex)

                {

                    MessageBox.Show("下载文件失败..."+ex.ToString());

                    ftpp.CloseConnection();

                    return;

                }

            }

            else

            {

                MessageBox.Show("FTP连接失败...");

            }

            //ftpp.CloseConnection();

        }

    }

}

完毕