谁能给我一个C#网络通信的例子

Question

you want tcp or ucp?

Answer 1

UDP:
    public class UDPServer
    {
        private System.Windows.Forms.ListBox lbDisplay;        private System.Threading.Thread myThread = null;        public UDPServer(System.Windows.Forms.ListBox lbDisplay_)
        {
            lbDisplay = lbDisplay_;
        }        public void Start()
        {
            if ( null != myThread )
            {
                myThread.Abort();
                myThread = null;
            }            myThread = new System.Threading.Thread(
                new System.Threading.ThreadStart(StartReceiv));
            myThread.Start();
        }        public void Dispose()
        {
            myThread.Abort();
        }        protected void StartReceiv()
        {
            /**
            //Creates an IPEndPoint to record the IP Address and port number of the sender. 
            // The IPEndPoint will allow you to read datagrams sent from any source.
            IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 8088);            //Creates a UdpClient for reading incoming data.
            UdpClient receivingUdpClient = new UdpClient(RemoteIpEndPoint);
            **/
            UdpClient receiver = new UdpClient(8088);
            while (true)
            {
                try
                {
                    IPEndPoint RemoteIpEndPoint = null;
                    Byte[] receiveBytes = receiver.Receive(ref RemoteIpEndPoint);
                    string returnData = System.Text.Encoding.UTF8.GetString(receiveBytes);
                    string msg = DateTime.Now + ":" 
                        + RemoteIpEndPoint.Address.ToString()
                        + "#" + RemoteIpEndPoint.Port.ToString()
                        + ": " + returnData.ToString();
                    lbDisplay.Items.Add(msg);
                    lbDisplay.SelectedIndex = lbDisplay.Items.Count - 1;
                    lbDisplay.SelectedIndex =  - 1;
                    //MessageBox.Show(msg);                    Console.WriteLine(msg);
                }
                catch ( Exception e )
                {
                    MessageBox.Show(e.Message); 
                    break;
                }
            }
        }
    }        private void btnSend_Click(object sender, System.EventArgs e)
        {
            UdpClient udpSender = new UdpClient();
            Byte[] buf = System.Text.Encoding.UTF8.GetBytes(txtMsg.Text);
            try
            {
                udpSender.Send(buf, buf.Length, "192.168.1.2", 8089);
            }
            catch ( Exception ee )
            {
                MessageBox.Show(ee.Message);    
            }
            udpSender.Close();
        }

Answer 2

erver = new TcpClient(POPServ.Text,110);      Status.Items.Clear();   try
   {
    
    NetStrm = Server.GetStream();    RdStrm= new StreamReader(Server.GetStream());    Status.Items.Add(RdStrm.ReadLine());
        
    Data = "USER "+ User1.Text+CRLF;    szData = System.Text.Encoding.ASCII.GetBytes(Data.ToCharArray());    NetStrm.Write(szData,0,szData.Length);    Status.Items.Add(RdStrm.ReadLine());
                    
    Data = "PASS "+ Passw.Text+CRLF;
    
    szData = System.Text.Encoding.ASCII.GetBytes(Data.ToCharArray());    NetStrm.Write(szData,0,szData.Length);    Status.Items.Add(RdStrm.ReadLine());
    
    Data = "STAT"+CRLF;    szData = System.Text.Encoding.ASCII.GetBytes(Data.ToCharArray());    NetStrm.Write(szData,0,szData.Length);    Status.Items.Add(RdStrm.ReadLine());
    ConnectBtn.Enabled = false;    DisconnectBtn.Enabled = true;    RetrieveBtn.Enabled = true;    
    //Cursor.Current = cr;   }   catch(InvalidOperationException err)
   {    Status.Items.Add("Error: "+err.ToString());   }
--------------------------------------------------------------------------这是在获取邮件时的代码:
string szTemp;
   string  encodedMai=Message.Text;
   Message.Text="";
   try
   {   
    Data = "RETR "+ Number.Text+CRLF;
    
    szData = System.Text.Encoding.GetEncoding(936).GetBytes(Data.ToCharArray());
  
    NetStrm.Write(szData,0,szData.Length);
   
    szTemp = RdStrm.ReadLine();
    if(szTemp[0]!='-') 
    {
        
     while(szTemp!=".")
     {
      Message.Text += szTemp;
      szTemp = RdStrm.ReadLine();
     }
    }
    else
    {
     Status.Items.Add(szTemp);
    }
        
    // back to normal cursor
    //Cursor.Current = cr;   }
   catch(InvalidOperationException err)
   {
    Status.Items.Add("Error: "+err.ToString());
   }
  }
  public TcpClient Server;
  public NetworkStream NetStrm;
  public StreamReader  RdStrm;
  public string Data;
  public byte[] szData;
  public string CRLF = "\r\n";