c#实现ftp功能

 string ftpServerIP = "apssdb";
        string ftpUserID = "ebideai";
        string ftpPassword = "ebideai";

        private void Upload(string filename)
        {
            FileInfo fileInf = new FileInfo(filename);
            string uri = "ftp://" + ftpServerIP + "/" + fileInf.Name;
            FtpWebRequest reqFTP;

            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileInf.Name));

            reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

            reqFTP.KeepAlive = false;

            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;

            reqFTP.UseBinary = true;

            reqFTP.ContentLength = fileInf.Length;

            int buffLength = 2048;

            byte[] buff = new byte[buffLength];
            int contentLen;

            FileStream fs = fileInf.OpenRead();
            try
            {
                Stream strm = reqFTP.GetRequestStream();

                contentLen = fs.Read(buff, 0, buffLength);

                while (contentLen != 0)
                {
                    strm.Write(buff, 0, contentLen);

                    contentLen = fs.Read(buff, 0, buffLength);
                }
                strm.Close();
                fs.Close();

                MessageBox.Show("success", "Upload Error");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Upload Error");
            }
        }

        private void Download(string filePath, string fileName)
        {
            FtpWebRequest reqFTP;

            try
            {
                FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);

                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileName));

                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;

                reqFTP.UseBinary = true;

                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();

                Stream ftpStream = response.GetResponseStream();

                long cl = response.ContentLength;

                int bufferSize = 2048;

                int readCount;

                byte[] buffer = new byte[bufferSize];

                readCount = ftpStream.Read(buffer, 0, bufferSize);

                while (readCount > 0)
                {
                    outputStream.Write(buffer, 0, readCount);

                    readCount = ftpStream.Read(buffer, 0, bufferSize);
                }

                ftpStream.Close();

                outputStream.Close();

                response.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            OpenFileDialog op = new OpenFileDialog();
            op.RestoreDirectory=true;
            if (DialogResult.OK==op.ShowDialog())
            {
            textBox1.Text=op.FileName;
            }

            //Upload(textBox1.Text);
            Upload(textBox1.Text);


        }

        private void button4_Click(object sender, EventArgs e)
        {
            Download(@"d:", "table 091901.sql");
        } 

http://www.cnblogs.com/kerryking/archive/2007/07/10/813079.aspx