[网络协议]2021-08-18

异步TCP客户端实现断线自动重连

在网上找了一个例子，测试发现了一些问题，主要是服务端没有开启，客户端就开启失败，物理网络断开后，无法自动连接。
修改后客户端实现了，被服务端踢下线，自动重连，等待服务端开启后，自动连接，物理网络断开恢复后，自动重连功能，亲自测试，功能完整。
客户端需要心跳发送，不然，物理网络断开恢复后，自动重连功能不能实现。

调用TCP客户端

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Timers;
using LJF;

class Program

{
    private static string _ip = "192.168.0.10";
    private static int _port = 8000;

    static void Main(string[] args)
    {
        AsyncTcpClient lJF = new AsyncTcpClient();
        lJF.ConnectServer(_ip, _port);
        while (true)
        {
            Thread.Sleep(1000);
            lJF.SendMsg("heartbeat");
        }
    }
}

异步TCP客户端

/***********************************
*    Description：异步TCP客户端
*    Mountpoint：这是一个单例脚本，无需挂载，直接调用即可
*    Date：2019.06.25
*    Version：unity版本2017.2.0f3
*    Author：LJF
***********************************/
using System.Net;
using System;
using System.Text;
using System.Diagnostics;
using System.IO;

namespace LJF
{
    //规范命名、添加注释、合理封装、限制访问权限    
    public class AsyncTcpClient
    {
        private string ip1;
        private int port1;
        byte[] ReadBytes = new byte[1024 * 1024];
        public static bool isWrite = false;
        //单例
        public static AsyncTcpClient Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new AsyncTcpClient();
                }
                return instance;
            }
        }
        private static AsyncTcpClient instance;

        System.Net.Sockets.TcpClient tcpClient;

        //连接服务器
        public void ConnectServer(string ip, int port)
        {
            //Debuger.EnableSave = true;
            ip1 = ip;
            port1 = port;
            try
            {
                tcpClient = new System.Net.Sockets.TcpClient();//构造Socket
                tcpClient.BeginConnect(IPAddress.Parse(ip), port, Lianjie, null);//开始异步
            }
            catch (Exception e)
            {
                displayDebug("初始化连接错误---，" + e.Message);
            }
        }

        //连接判断
        void Lianjie(IAsyncResult ar)
        {
            if (!tcpClient.Connected)
            {
                displayDebug("判断连接---，服务器未开启，尝试重连。。。。。。");        
                tcpClient = null;                
                try
                {
                    ConnectServer(ip1, port1);
                }
                catch (Exception e)
                {
                    displayDebug("判断连接---从新连接错误，" + e.Message);
                }
            }
            else
            {
                displayDebug("判断连接---，连接上了");               
                try
                {
                    tcpClient.EndConnect(ar);//结束异步连接
                    tcpClient.GetStream().BeginRead(ReadBytes, 0, ReadBytes.Length, ReceiveCallBack, null);
                    isWrite = true;
                }
                catch (Exception e)
                {
                    displayDebug("判断连接错误---," + e.Message);
                }
            }
        }


        //接收消息
        void ReceiveCallBack(IAsyncResult ar)
        {
            try
            {
                int len = tcpClient.GetStream().EndRead(ar);//结束异步读取
                if (len > 0)
                {

                    string str = Encoding.GetEncoding("GB2312").GetString(ReadBytes, 0, len);
                    str = Uri.UnescapeDataString(str);
                    //将接收到的消息写入日志
                    //Debuger.Log(string.Format("收到主机:{0}发来的消息|{1}", ip1, str));
                    displayDebug(str);
                    writerCsv(getTime(str), "log");
                    tcpClient.GetStream().BeginRead(ReadBytes, 0, ReadBytes.Length, ReceiveCallBack, null);
                }
                else
                {
                    tcpClient = null;
                    displayDebug("接收消息---连接断开,尝试重连。。。。。。");
                    ConnectServer(ip1, port1);
                }
            }
            catch (Exception e)
            {
                displayDebug("接收消息错误---，" + e.Message);
                tcpClient = null;
                displayDebug("接收消息错误---网络断开,尝试重连。。。。。。");
                ConnectServer(ip1, port1);
            }
        }

        //发送消息
        public void SendMsg(string msg)
        {
            try
            {
                if (tcpClient != null && tcpClient.Client.Connected)
                {
                    byte[] msgBytes = Encoding.GetEncoding("GB2312").GetBytes(msg);
                    tcpClient.GetStream().BeginWrite(msgBytes, 0, msgBytes.Length, (ar) =>
                    {
                        tcpClient.GetStream().EndWrite(ar);//结束异步发送
                    }, null);//开始异步发送
                }
                else
                {
                    displayDebug("发送消息---，网络断开，尝试重连。。。。。。");     
                }
            }
            catch (Exception e)
            {
                displayDebug("发送消息错误---，" + e.Message);               
            }

        }

        /// <summary>
        /// 断开连接
        /// </summary>
        public void Close()
        {
            if (tcpClient != null && tcpClient.Client.Connected)
                tcpClient.Close();
            if (!tcpClient.Client.Connected)
            {
                tcpClient.Close();//断开挂起的异步连接
            }
        }



        private void writerCsv(String data, string name)
        {
            try

            {
                string mTime = DateTime.Now.ToString("yyyyMMdd");

                //string path = System.AppDomain.CurrentDomain.BaseDirectory +"login\\"+ mTime + name + ".csv";

                //获取当前文件夹路径
                string currPath = System.AppDomain.CurrentDomain.BaseDirectory;
                //检查是否存在文件夹
                string subPath = currPath + "\\login\\";
                if (false == System.IO.Directory.Exists(subPath))
                {
                    //创建文件夹
                    System.IO.Directory.CreateDirectory(subPath);
                }

                subPath += mTime + name + ".csv";

                FileStream fs = new FileStream(subPath, FileMode.Append);//文本加入不覆盖

                StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);//转码

                sw.WriteLine(data);

                //清空缓冲区
                sw.Flush();
                //关闭流
                sw.Close();
                fs.Close();               
            }
            catch (Exception)
            {
                displayDebug("数据保存失败！");
            }
        }

        private void displayDebug(string msg)
        {
            string log = getTime(msg);
            Console.WriteLine(log);            
        }

        private string getTime(string msg)
        {
            string mTime = DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss");
            mTime += " : ";
            mTime += msg;
            return mTime;
        }

       
    }
}