c# FTP 上传文件代码

//关键代码
using System.Net.WebRequestMethods.Ftp;

NetworkCredential nCredl=new NetworkCredential(FtpUser,FtpPwd);

private bool UpFile(string filename)
            {
                bool status = false;
                FtpWebRequest ftpQ = (FtpWebRequest)WebRequest.Create(ss.FtpUrl);
                ftpQ.KeepAlive = false;
                FtpWebResponse response=null;

                ftpQ.Credentials = nCredl;

                ftpQ.Method = WebRequestMethods.Ftp.AppendFile;

                    FileStream fs = new FileStream(filename, FileMode.Open,FileAccess.Read,FileShare.Read);

                    byte[] bits = null;
                    if (IsLimitSpeed)
                    {
                        bits = new byte[speed];
                    }
                    else
                    {
                        bits = new byte[102400];
                    }
                    
                    int rlen = 0;
                    decimal filelen=(decimal)fs.Length;
                    long rdcount = 0;
                    int v=0;
                    long sd = getFileSize();

                    Stream requestStream = null;
                    if (sd == -1) sd = 0;
                    fs.Position = sd;
                    rdcount += sd;

                    try
                    {

                        requestStream = ftpQ.GetRequestStream();

                        while (0 != (rlen = fs.Read(bits, 0, bits.Length)))
                        {
                            requestStream.Write(bits, 0, rlen);
                            requestStream.Flush();
                            rdcount += rlen;
                            if (Ev_UpFleSub != null)
                            {
                                v = (int)(((decimal)rdcount / filelen) * 100);
                                Ev_UpFleSub(v, rdcount, this.ss, this.pb);
                            }
                            if (IsLimitSpeed)
                            {
                                System.Threading.Thread.Sleep(500);
                            }
                        }
                        if (requestStream != null)
                        {
                            requestStream.Close();
                        }
                        fs.Close();
                    }
                    catch (Exception ex)
                    {
                        if (fs != null)
                        {
                            fs.Dispose();
                        }
                        try
                        {
                            if (requestStream != null)
                            {
                                GC.ReRegisterForFinalize(requestStream);
                            }
                        }catch{}
                   
                        throw ex;
                    }

                    
                    return status;
            }