C#Socket通讯(二)

/// 线程执行体,转发消息 
        /// </summary> 
        /// <param name="obj">传递给线程执行体的用户名，用以与用户通信 </param> 
        private void ThreadFunc(object obj) 
        { 
            //通过转发表得到当前用户套接字 
            Socket clientSkt = _transmit_tb[obj] as Socket; 
          //主循环 
            while (true) 
            { 
                try 
                { //接受第一个数据包。 
                    //由于程序逻辑结构简单，所以在这里对客户机发送的第一个包内容作逐一判断， 
                    //这里的实现不够优雅，但不失为此简单模型的一个解决之道。 
                    byte[] packetBuff = new byte[_maxPacket]; 
                    clientSkt.Receive(packetBuff); 
                    string _str = Encoding.Unicode.GetString(packetBuff).TrimEnd('\0'); 
                    //如果是发给不在线好友的信息 
                    if (_str.StartsWith("cmd::FriendMessage")) 
                    { 
                        string UserName = _str.Substring("cmd::FriendMessage".Length, 20).Trim(); 
                        string MessageS = _str.Substring("cmd::FriendMessage".Length + 20, _str.Length - "cmd::FriendMessage".Length - 20); 
                        SaveMessage(obj as string, UserName, MessageS); 
                        continue; 
                    } 
                    //如果是离线请求 
                    if (_str.StartsWith("cmd::RequestLogout")) 
                    { 
                        _transmit_tb.Remove(obj); 
                        UpdateFriendList((string)obj, false, ""); 
                      // string svrlog = string.Format("[系统消息]用户 {0} 在 {1} 已断开... 当前在线人数: {2}\r\n\r\n", obj, DateTime.Now, _transmit_tb.Count); 
                      // Console.WriteLine(svrlog); 
                        //向所有客户机发送系统消息 
                      
                        //foreach (DictionaryEntry de in _transmit_tb) 
                        //{ 
                        //    string _clientName = de.Key as string; 
                        //    Socket _clientSkt = de.Value as Socket; 
                        //    _clientSkt.Send(Encoding.Unicode.GetBytes(svrlog)); 
                        //} 
                        Thread.CurrentThread.Abort(); 
                    } 
                    //如果是请求好友列表 
                    if (_str.StartsWith("cmd::RequestFriendList")) 
                    { 
                        SerializeFriendList(obj, clientSkt);                      
                        // 将该用户不在线时的信息发送给用户 
                        DataTable TabMessage = ReadMessage(obj as string); 
                        if (TabMessage != null) 
                        { 
                            foreach (DataRow myrow in TabMessage.Rows) 
                            { 
                                if (myrow["SendUserName"].ToString() == "System::Message") 
                                { 
                                    clientSkt.Send(Encoding.Unicode.GetBytes(myrow["Message"].ToString())); 
                                } 
                                else 
                                { 
                                    clientSkt.Send(Encoding.Unicode.GetBytes("cmd::FriendMessage" + myrow["SendUserName"].ToString().PadRight(20, ' ') + myrow["Message"].ToString()));
                                } 
                            } 
                        } //这里不需要再继续接受后继数据包了，跳出当前循环体。 
                        continue; 
                    } 
                    ////如果是请求好友列表 
                    //if (_str.StartsWith("cmd::RequestOnLineList")) 
                    //{ 
                    //    byte[] onlineBuff = SerializeOnlineList(); 
                    //    //先发送响应信号，用户客户机的判断 
                    //    clientSkt.Send(Encoding.Unicode.GetBytes("cmd::RequestOnLineList")); 
                    //    clientSkt.Send(onlineBuff); 
                    //    //这里不需要再继续接受后继数据包了，跳出当前循环体。 
                    //    continue; 
                    //} //查找用户 
                    if (_str.StartsWith("Find::FindFriend")) 
                    { 
                        DataTable TabFind = TabUser.Clone(); 
                        DataRow [] FindRow =null ; 
                        string UserName = _str.Substring("Find::FindFriend".Length, _str.Length - "Find::FindFriend".Length); 
                        if (UserName.Equals("Find::WhoOnLine")) 
                        { //看谁在线 
                            FindRow = TabUser.Select(" ZX = 1"); 
                        } 
                     else//精确查找 
                        { 
                            FindRow = TabUser.Select("UserName = '" + UserName + "'"); 
                        } 
                        foreach (DataRow myrow in FindRow) 
                        { 
                            TabFind.ImportRow(myrow); 
                        } 
              
                        clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriend")); 
                        IFormatter format = new BinaryFormatter(); 
                        MemoryStream stream = new MemoryStream(); 
                        format.Serialize(stream, TabFind); 
                        stream.Position = 0; 
                        byte[] ret = new byte[_maxPacket]; 
                        int count = 0; 
                        count = stream.Read(ret, 0, _maxPacket); 
                        while (count >0) 
                        { 
                            clientSkt.Send(ret); 
                          count = stream.Read(ret, 0, _maxPacket); 
                        } 
                        clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriendEnd")); 
                        stream.Close(); 
                        TabFind = null; 
                        FindRow = null; //这里不需要再继续接受后继数据包了，跳出当前循环体。 
                        continue; 
                    } //请求添加好友 
                    if (_str.StartsWith("Find::AddFriendAsk")) 
                    { 
                        string UserName = _str.Substring("Find::AddFriendAsk".Length, _str.Length - "Find::AddFriendAsk".Length); 
                        //通过转发表查找接收方的套接字 
                        if (_transmit_tb.Count != 0 && _transmit_tb.ContainsKey(UserName)) 
                        { 
                            Socket receiverSkt = _transmit_tb[UserName] as Socket; 
                            receiverSkt.Send(Encoding.Unicode.GetBytes("Find::AddFriendAsk" + obj as string)); 
                        } 
                        //这里不需要再继续接受后继数据包了，跳出当前循环体。 
                        continue; 
                    }