//檔案流
            FileStream fs = new FileStream("", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
            byte[] b = new byte[1024];
            int i = fs.Read(b, 0, b.Length);
            fs.Write(b, 0, b.Length);
            fs.Flush();//只有在寫時候才會用到FLUSH清記憶體
            fs.Close();

            //文字流
            StreamReader sr = new StreamReader("", Encoding.UTF32);
            sr.Read();
            sr.Close();

            StreamWriter sw = new StreamWriter("", true, Encoding.UTF8);
            sw.WriteLine("abcd");
            sw.Flush();//只有在FLUSH後才正真將內容寫入檔案中。要麼就在CLOSE後才會寫入檔案。在主發前一直是儲存在綬存中。
            sw.Close();

            //網路流一般是提供給網路TCPClient和TCPListener用的
            IPHostEntry iphostentry = Dns.GetHostEntry(Dns.GetHostName());
            IPAddress ipaddress = iphostentry.AddressList[0];
            IPEndPoint ipendpoint = new IPEndPoint(ipaddress, 8060);
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            s.Connect(ipendpoint);
            //網路套接字的傳送和接收
            s.Send(b);
            s.Receive(b);

            //NetworkStream nws = new NetworkStream(s);
            //nws.Write(b, 0, b.Length);
            //nws.Read(b, 0, b.Length);
            //nws.Flush();
            //nws.Close();

            //客戶端
            TcpClient tcpclient = new TcpClient();//若不指定本機的IP及埠，預設為本機的IP和0號埠
            tcpclient.Connect("www.163.com

", 8086);//遠端伺服器IP及埠
            NetworkStream nws1 = tcpclient.GetStream();
            nws1.Write(b, 0, b.Length);
            nws1.Read(b, 0, b.Length);
            //伺服器端
            TcpListener tcplistener = new TcpListener(8086);//指定伺服器端監聽埠
            tcplistener.Start();//開始監聽
            TcpClient tcpclient1 = tcplistener.AcceptTcpClient();//接受客戶端的請求。
            nws1 = tcpclient1.GetStream();
            nws1.Read(b, 0, b.Length);
            nws1.Write(b, 0, b.Length);