TCP .NET（开发人员如何使用）

1. 可靠性

TCP 使用序列号、确认以及重传等技术来保证数据的可靠传递。 发送者发送数据包，并等待接收者确认数据包已成功传递。 如果在预定时间内未收到确认，发送者会重传数据包。此可靠性机制有助于避免传输数据丢失或损坏。

2. 面向连接的通信

在发送数据之前，TCP协议在发送者和接收者之间建立连接。 在连接设置期间，发送者和接收者通过三次握手过程来实现同步和决定通信设定。数据可以在双方之间往返传递，直到连接中断。

3. 流量管理

TCP使用流量控制方法来管理数据从发送者到接收者的传输速度。 流量控制使用滑动窗口方法，以防止发送者发送过多数据给接收者。 发送者可以响应接收者公布的可用缓冲区空间来调整其传输速率。 通过这样做，有效利用网络资源，避免拥塞或缓冲区溢出。

TCP代码分为两个部分：一个是服务器，另一个是客户端。 服务器代码使用IP地址和端口将消息发送到客户端，客户端接收数据并相应处理。

TCP服务器代码

// Basic TCP Server Code in C#
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;

class TcpServer
{
    static void Main()
    {
        // Set up the server endpoint with localhost IP address and a specified port
        var endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 57472);

        // Create a new TcpListener and start listening for incoming connections
        TcpListener listener = new TcpListener(endPoint);
        listener.Start();
        Console.WriteLine("Server listening...");

        // Accept a TcpClient once a connection attempt is made
        TcpClient client = listener.AcceptTcpClient();
        Console.WriteLine("Client connected");

        // Obtain a NetworkStream object for reading and writing data
        NetworkStream stream = client.GetStream();
        StreamWriter writer = new StreamWriter(stream);

        // Write a message to the client's stream and flush to ensure it's sent
        writer.WriteLine("Hello from the server");
        writer.Flush();

        Console.WriteLine("Message sent from server");
        // Close the client connection
        client.Close();

        // Stop the server listener after communication
        listener.Stop();
    }
}

// Basic TCP Server Code in C#
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;

class TcpServer
{
    static void Main()
    {
        // Set up the server endpoint with localhost IP address and a specified port
        var endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 57472);

        // Create a new TcpListener and start listening for incoming connections
        TcpListener listener = new TcpListener(endPoint);
        listener.Start();
        Console.WriteLine("Server listening...");

        // Accept a TcpClient once a connection attempt is made
        TcpClient client = listener.AcceptTcpClient();
        Console.WriteLine("Client connected");

        // Obtain a NetworkStream object for reading and writing data
        NetworkStream stream = client.GetStream();
        StreamWriter writer = new StreamWriter(stream);

        // Write a message to the client's stream and flush to ensure it's sent
        writer.WriteLine("Hello from the server");
        writer.Flush();

        Console.WriteLine("Message sent from server");
        // Close the client connection
        client.Close();

        // Stop the server listener after communication
        listener.Stop();
    }
}

在这个服务器代码中，我们创建了一个 TCP 服务器代码，将数据包发送到连接的客户端。 服务器接收传入的连接并通过TCP socket 发送信息。

TCP 客户端代码

// TCP client code
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;

class TcpClientExample
{
    static void Main()
    {
        // Set up the client to connect to the same endpoint as the server
        var endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 57472);

        // Initialize a new TcpClient and connect to the server endpoint
        TcpClient client = new TcpClient();
        client.Connect(endPoint);

        // Use a NetworkStream to read data received from the server
        NetworkStream stream = client.GetStream();
        StreamReader reader = new StreamReader(stream);

        // Read the response sent by the server and display it
        string response = reader.ReadLine();
        Console.WriteLine($"Message from server: {response}");

        // Close the connection once done
        client.Close();
    }
}

// TCP client code
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;

class TcpClientExample
{
    static void Main()
    {
        // Set up the client to connect to the same endpoint as the server
        var endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 57472);

        // Initialize a new TcpClient and connect to the server endpoint
        TcpClient client = new TcpClient();
        client.Connect(endPoint);

        // Use a NetworkStream to read data received from the server
        NetworkStream stream = client.GetStream();
        StreamReader reader = new StreamReader(stream);

        // Read the response sent by the server and display it
        string response = reader.ReadLine();
        Console.WriteLine($"Message from server: {response}");

        // Close the connection once done
        client.Close();
    }
}

在上述客户端代码中，该代码连接到 TCP socket并读取从TCP服务器接收到的字符串信息，然后在控制台上显示该信息。 此示例说明了在 .NET 环境中使用 TCP 的基本客户端-服务器通信。