利用TcpClient，简单的tcp消息收发

TcpClient和以前学过的对象，相对关系示意图如下：

借助有连接的特性，它封装了很多需要一起使用的对象，用起来也更加方便。

作为服务端时，它一般配合TcpListener使用。

由监听者创建的所有客户端，都使用与监听者相同的ipendpoint。（实现上，可以理解为不同的socket指向相同的ipendpoint）

例：

说明：服务端有一个监听者（TcpListener），接收到连接请求后，建立连接给一个客户端（TcpClient）。

利用流读取器（StreamReader）获取传递过来的信息并显示。

客户端建立一个客户端对象（TcpClient），连接服务端后就可以利用流写入对象（StreamWriter）发送数据。

代码如下：

服务端：

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.IO;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpListener listener = new TcpListener(IPAddress.Any, 9000);
            TcpClient client = new TcpClient();
            StreamReader sr;
            string msg;
            listener.Start();
            client = listener.AcceptTcpClient();
            sr = new StreamReader(client.GetStream());
            do
            {
                msg = sr.ReadLine();
                Console.WriteLine(msg);
            } while (msg.ToLower()!="exit");
        }
    }
}

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.IO;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpClient tcp = new TcpClient();
            string msg;
            IPEndPoint iPEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9000);
            tcp.Connect(iPEndPoint);
            StreamWriter sw = new StreamWriter(tcp.GetStream());
            do
            {
                msg = Console.ReadLine();
                sw.WriteLine(msg);
                sw.Flush();
            } while (msg.ToLower()!="exit");
        }
    }
}

运行效果：

---

在此基础智商，两边互相收发，也很简单。

服务端代码：

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.IO;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpListener listener = new TcpListener(IPAddress.Any, 9000);
            TcpClient client;
            StreamReader reader;
            StreamWriter writer;
            string msg;
            listener.Start();
            client= listener.AcceptTcpClient();
            reader = new StreamReader(client.GetStream());
            writer = new StreamWriter(client.GetStream());
            do
            {
                Console.WriteLine("等待接收数据：");
                msg=reader.ReadLine();
                Console.WriteLine(msg);
                Console.WriteLine("等待发送数据：");
                msg = Console.ReadLine();
                writer.WriteLine(msg);
                writer.Flush();
            } while (msg.ToLower()!="exit");
        }
    }
}

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.IO;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpClient client=new TcpClient();
            StreamReader reader;
            StreamWriter writer;
            string msg;
            client.Connect(IPAddress.Parse("127.0.0.1"),9000);
            reader = new StreamReader(client.GetStream());
            writer = new StreamWriter(client.GetStream());
            do
            {
                Console.WriteLine("等待发送数据：");
                msg = Console.ReadLine();
                writer.WriteLine(msg);
                writer.Flush();
                Console.WriteLine("等待接收数据：");
                msg = reader.ReadLine();
                Console.WriteLine(msg);

            } while (msg.ToLower() != "exit");
        }
    }
}

运行效果：

---

当启用另外一个单独的线程去接收数据的时候，发送和接收就可以互不干扰了。

服务端：

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.IO;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpListener listener = new TcpListener(IPAddress.Any, 9000);
            TcpClient client;
            StreamWriter writer;
            string msg;
            listener.Start();
            client= listener.AcceptTcpClient();
            Task t = new Task(getMessage, client);
            t.Start();
            writer = new StreamWriter(client.GetStream());
            do
            {
                Console.WriteLine("等待发送数据：");
                msg = Console.ReadLine();
                writer.WriteLine(msg);
                writer.Flush();
            } while (msg.ToLower()!="exit");
        }
        static void getMessage(object tcp)
        {
            StreamReader reader;
            TcpClient client = (TcpClient)tcp;
            reader = new StreamReader(client.GetStream());
            string msg;
            do
            {
                Console.WriteLine("等待接收数据：");
                msg = reader.ReadLine();
                Console.WriteLine(msg);
            } while (msg.ToLower() != "exit");
        }
    }
}

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.IO;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpClient client=new TcpClient();
            StreamWriter writer;
            string msg;
            client.Connect(IPAddress.Parse("127.0.0.1"), 9000);
            Task t = new Task(getMessage, client);
            t.Start();
            writer = new StreamWriter(client.GetStream());
            do
            {
                Console.WriteLine("等待发送数据：");
                msg = Console.ReadLine();
                writer.WriteLine(msg);
                writer.Flush();
            } while (msg.ToLower() != "exit");
        }
        static void getMessage(object tcp)
        {
            StreamReader reader;
            TcpClient client = (TcpClient)tcp;
            reader = new StreamReader(client.GetStream());
            string msg;
            do
            {
                Console.WriteLine("等待接收数据：");
                msg = reader.ReadLine();
                Console.WriteLine(msg);
            } while (msg.ToLower() != "exit");
        }
    }
}

运行结果：

---

思考：重复监听，连接多客户端。在任意接收线程收到消息后，向各客户端群发消息。即构建聊天室程序。

提示：多客户端可以存在List里面。