急，ftp下载文件问题

Question

string server = ftpip;
                    string username = ftpusername;
                    string password = ftppassword;
                    FtpWebRequest request =
                        (FtpWebRequest)WebRequest.Create(server);
                    request.Credentials = new NetworkCredential(username, password);
                    request.Method = WebRequestMethods.Ftp.ListDirectory;
                    response = (FtpWebResponse)request.GetResponse();
                    stream = response.GetResponseStream();                    //  获取文件列表;
                    StreamReader reader = new StreamReader(stream);
                    string content = reader.ReadToEnd();
                    string[] files = content.Split('\n');
                    int s = files.Length;
                    reader.Close();                    //下载列表文件
                    serverDirectory = null;
                    Uri baseUri = new Uri(server);                    if (File.Exists(xmlad ))
                    {
                        File.Delete(@xmlad);
                    }
                    for (int i = 0; i <= s - 2; i++)
                    {
                        if (File.Exists(downaddress + @"\" + files[i]))
                        {                            //i++;                        }
                        else
                        {
                            string filename = files[i].ToString().Trim();
                            string fullFilename = serverDirectory + @"/" + filename;
                            Uri uri = new Uri(baseUri, fullFilename);
                            request = (FtpWebRequest)WebRequest.Create(uri);
                            request.Credentials = new NetworkCredential(username, password);
                            request.Method = WebRequestMethods.Ftp.DownloadFile;
                            response = (FtpWebResponse)request.GetResponse();
                            inStream = response.GetResponseStream();
                            //  inStream.Length                                             File.Create(downaddress + filename);
                            outStream = File.OpenWrite(downaddress+ @"\" + filename);
                            byte[] buffer = new byte[1024];                            int size = 0;
                            while ((size = inStream.Read(buffer, 0, 1024)) > 0)
                            {
                            
                                outStream.Write(buffer, 0, size);
                            }
                            outStream.Flush();
                            outStream.Close();                        }用这段代码下载文件，如果文件已经存在，能否改写？

Answer 1

我的意思文件名相同，内容不一定相同，如果内容不同，能否改写