private void button1_Click(object sender, EventArgs e)
   {
     try
     {
       int port = int.Parse(txt_port.Text);
       string host = txt_ip.Text;
       //创建终结点
       IPAddress ip = IPAddress.Parse(host);
       IPEndPoint ipe = new IPEndPoint(ip, port);
       //创建Socket并开始监听
       newsock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); //创建一个Socket对象，如果用UDP协议，则要用SocketTyype.Dgram类型的套接字
       newsock.Bind(ipe);  //绑定EndPoint对象
       newsock.Listen(0);  //开始监听
       //为新建立的连接创建新的Socket
       acceptClientThread = new Thread(new ThreadStart(AcceptClient));
       acceptClientThread.Start();
       SetText("开始监听");
     }
     catch (Exception exp)
     {
       CommonFunction.WriteLog(exp, exp.Message);
     }
   }

/// <summary>
    /// 接受客户端，可接受多个客户端同时连入，并对连入的客户端注册到客户端列表
    /// </summary>
    public void AcceptClient()
    {
      try
      {
        while (true)
        {
          Socket client = newsock.Accept();
          ip = client.Handle;
          RegeistUser(client.Handle, client);
          Thread clientThread = new Thread(new ParameterizedThreadStart(ReceiveData));
          object o = client;
          clientThread.Start(o);
        }
      }
      catch (Exception exp)
      {
        CommonFunction.WriteLog(exp, exp.Message);
      }
    }

/// <summary>
    /// 接收客户端数据并，转发到目标客户端。
    /// </summary>
    public void ReceiveData(object o)
    {
      try
      {
        while (true)
        {
          Socket client = (Socket)o;
          string recvStr = "";
          byte[] recvBytes = new byte[1024];
          int bytes;
          bytes = client.Receive(recvBytes, recvBytes.Length, 0); //从客户端接受消息
          recvStr = Encoding.UTF8.GetString(recvBytes, 0, bytes);
          SendMessage(client, recvStr);
          SetText(recvStr);
          CommonFunction.WriteErrorLog(recvStr);
        }
      }
      catch (Exception exp)
      {
        CommonFunction.WriteLog(exp, exp.Message);
      }
    }

/// <summary>
   /// 判断是用户注册还是发送消息
   /// </summary>
   /// <param name="p_strMessage"></param>
   public void SendMessage(Socket client,string p_strMessage)
   {
     if (p_strMessage.StartsWith("@"))
     {
       RegeistUser(p_strMessage, client);
     }
     else if (p_strMessage.StartsWith(">"))
     {
       
       DeleteClident(p_strMessage);
     }
     else
     {
       //SendMessageToTarget(p_strMessage);
       SendAllMessage(p_strMessage);
     }
   }

/// <summary>
    /// 将socket注册为指定用户名
    /// </summary>
    /// <param name="user"></param>
    /// <param name="ss"></param>
    public void RegeistUser(string user, Socket ss)
    {
      user = user.Remove(0, 1);
      userSocketDict.Add(user, ss);
      SendOneMessage(ss, "欢迎" + user + "连入！");
      RefreshClient();
    }

/// <summary>
    /// 从客户端字典中移除客户端
    /// </summary>
    /// <param name="p_strMessage"></param>
    public void DeleteClident(string p_strMessage)
    {
      p_strMessage = p_strMessage.Remove(0, 1);
      userSocketDict.Remove(p_strMessage);
      RefreshClient();
    }

/// <summary>
    /// 群发消息
    /// </summary>
    /// <param name="p_strsend"></param>
    public void SendAllMessage(string p_strsend)
    {
      //MessageBox.Show(p_strsend);
      foreach (string item in userSocketDict.Keys)
      {
        byte[] bs = Encoding.UTF8.GetBytes(p_strsend);
        userSocketDict[item].Send(bs, bs.Length, 0); 
      }
    }

public delegate void SetTextHandler(string text);
    /// <summary>
    /// 给文本框赋值
    /// </summary>
    /// <param name="text"></param>
    private void SetText(string text)
    {
      if (rich_back.InvokeRequired == true)
      {
        SetTextHandler set = new SetTextHandler(SetText);//委托的方法参数应和SetText一致 
        rich_back.Invoke(set, new object[] { text }); //此方法第二参数用于传入方法,代替形参text 
      }
      else
      {
        rich_back.Text += "\n" + text;
      }
 
    }

private void button1_Click(object sender, EventArgs e)
    {
      try
      {
        user = txt_name.Text;
        int port = int.Parse(txt_port.Text);
        string host = txt_ip.Text;
        //创建终结点EndPoint
        IPAddress ip = IPAddress.Parse(host);
        IPEndPoint ipe = new IPEndPoint(ip, port);  //把ip和端口转化为IPEndPoint的实例
        //创建Socket并连接到服务器
        Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);  // 创建Socket
        cc = c;
        c.Connect(ipe); //连接到服务器
        clientThread = new Thread(new ThreadStart(ReceiveData));
        clientThread.Start();
        //向服务器发送本机用户名，以便服务器注册客户端
        SendMessage("@" + txt_name.Text);
      }
      catch (ArgumentException ex)
      {
        Console.WriteLine("argumentNullException:{0}", ex);
      }
      catch (SocketException exp)
      {
        Console.WriteLine("SocketException:{0}",exp);
      }
    }

private void button3_Click(object sender, EventArgs e)
    {
      if (""==txt_target.Text)
      {
        MessageBox.Show("未选择对话人物");
        return;
      }
      //向服务器发送信息
      string sendStr = txt_name.Text + "@" + target + ":" + txt_message.Text;
      SendMessage(sendStr);
      rch_back.Text += "\n" + sendStr;
      txt_message.Text = "";
    }

private void button2_Click(object sender, EventArgs e)
    {
      try
      {
        SendMessage(">" + txt_name.Text);
        //cc.Disconnect(true);
        //cc.Shutdown(SocketShutdown.Both);
        //cc.Close();
      }
      catch (Exception exp)
      {
        CommonFunction.WriteLog(exp, exp.Message);
      }
    }