Biegral Blog

using System;
using System.Collections.Generic;
using System.Text;
using System.Net.Sockets;
using System.Threading;

namespace EventBase
{
    /*解决Socket的粘包处理
     使用方法
        A2DTcpClient client = new A2DTcpClient("127.0.0.1", 5000);
        client.NewMessageReceived += new MessageReceived(client_NewMessageReceived);
        client.Connect();
        client.Send("HELLO");
        client.Close();
        static void client_NewMessageReceived(string msg)
        {
            Console.WriteLine(msg);
        }
     */
    public delegate void MessageReceived(string msg);
    public class A2DTcpClient
    {
        public const string terminateString = "\r\n"; //消息的结尾标记
        public const int receiveBufferSize = 1024; //缓冲区大小

        private string RemoteServer { get; set; }
        private int RemotePort { get; set; }
        private TcpClient tcpClient;

        public event MessageReceived NewMessageReceived;

        public A2DTcpClient(string remoteServer, int remotePort)
        {
            this.RemotePort = remotePort;
            this.RemoteServer = remoteServer;
            tcpClient = new TcpClient();
        }

        public void Connect()
        {
            if (tcpClient.Connected)
                throw new Exception("Connected, cannot re-connect.");
            tcpClient.Connect(this.RemoteServer, this.RemotePort);
            ThreadPool.QueueUserWorkItem(new WaitCallback(ReceiveMessage), tcpClient.Client);
            Thread.Sleep(2000);//强制暂停，为了上面的线程运行
        }

        public void Close()
        {
            if (!tcpClient.Connected)
                throw new Exception("Closed, cannot re-close.");
            tcpClient.Close();
        }

        StringBuilder sb = new StringBuilder(); //这个是用来保存：接收到了的，但是还没有结束的消息
        public void ReceiveMessage(object state) //这个函数会被以线程方式运行
        {
            Socket socket = (Socket)state;
            while (true)
            {
                byte[] buffer = new byte[receiveBufferSize]; //buffer大小，此处为1024
                int receivedSize = socket.Receive(buffer);

                string rawMsg = System.Text.Encoding.Default.GetString(buffer, 0, receivedSize);
                int rnFixLength = terminateString.Length; //这个是指消息结束符的长度，此处为\r\n
                for (int i = 0; i < rawMsg.Length; ) //遍历接收到的整个buffer文本
                {
                    if (i <= rawMsg.Length - rnFixLength)
                    {
                        if (rawMsg.Substring(i, rnFixLength) != terminateString) //非消息结束符，则加入sb
                        {
                            sb.Append(rawMsg[i]);
                            i++;
                        }
                        else
                        {
                            this.OnNewMessageReceived(sb.ToString()); //找到了消息结束符，触发消息接收完成事件
                            sb.Clear();
                            i += rnFixLength;
                        }
                    }
                    else
                    {
                        sb.Append(rawMsg[i]);
                        i++;
                    }
                }
            }
        }
        private void OnNewMessageReceived(string msg)
        {
            if (this.NewMessageReceived != null)
                this.NewMessageReceived.Invoke(msg);
        }

        public void Send(string str)
        {
            if (!this.tcpClient.Connected)
                throw new Exception("Closed, cannot send data.");
            str += terminateString;
            byte[] byteArray = System.Text.Encoding.Default.GetBytes(str);
            this.tcpClient.Client.Send(byteArray);
        }
    }
}