C#.NET TCP、UDP、Socket
进程间通信的方式主要是有命名管道、消息队列、共享内存、Socket通信,个人用的最多的是Sokcet相关。
Socket
Socket是传输通信协议么?No,Socket是一种传输层和应用层之间、用于实现网络通信的编程接口。Socket可以使用各种协议如TCP、UDP协议实现进程通信,TCP/UDP才是传输通信协议
Socket位于传输层与应用层之间,接口在System.Net.Sockets命名空间下。下面是Socket以TCP通信的DEMO:
//创建一个 Socket 实例
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
//连接到服务器
clientSocket.Connect(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8000));
//发送数据
string message = "Hello, Server!";
byte[] data = Encoding.ASCII.GetBytes(message);
clientSocket.Send(data);
//接收数据
byte[] buffer = new byte[1024];
int bytesRead = clientSocket.Receive(buffer);
Debug.WriteLine(Encoding.ASCII.GetString(buffer, 0, bytesRead));
clientSocket.Close();
TcpClient/UdpClient
TCP/UDP均是位于传输层的通信协议,所以Socket的使用也是位于传输层的通信操作
TCP是面向连接,提供可靠、顺序的数据流传输。用于一对一的通信,即一个TCP连接只能有一个发送方和一个接收方。详细连接方式是,先通过三次握手建立连接、然后传输数据,传输数据完再通过4次挥手关闭连接。所以适用于需要数据完整性和可靠传输的场景
而UDP则是无连接的,不需要建立和维护连接状态,不提供确认机制,也不重传丢失的数据报,但也因此传输实时性高,适合低延时、数据量小、广播场景
基于Socket抽象编程接口,TCP、UDP构建更高级别抽象网络编程TcpClient、UdpClient,它们用于简化TCP网络编程中的常见任务
TcpClient、UdpClient是 .NET 提供的用于方便管理TCP和UDP网络通信的类,下面是对应的Demo
Tcp服务端:
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class TcpServerExample
{
public static void Main()
{
TcpListener listener = new TcpListener(“127.0.0.1", 8000);
listener.Start();
Console.WriteLine("Server is listening on port 8000...");
TcpClient client = listener.AcceptTcpClient();
NetworkStream stream = client.GetStream();
byte[] data = new byte[1024];
int bytesRead = stream.Read(data, 0, data.Length);
Console.WriteLine("Received: " + Encoding.ASCII.GetString(data, 0, bytesRead));
byte[] response = Encoding.ASCII.GetBytes("Hello, Client!");
stream.Write(response, 0, response.Length);
stream.Close();
client.Close();
listener.Stop();
}
}
TCP客户端:
using System;
using System.Net.Sockets;
using System.Text;
class TcpClientExample
{
public static void Main()
{
TcpClient client = new TcpClient("127.0.0.1", 8000);
NetworkStream stream = client.GetStream();
byte[] message = Encoding.ASCII.GetBytes("Hello, Server!");
stream.Write(message, 0, message.Length);
byte[] data = new byte[1024];
int bytesRead = stream.Read(data, 0, data.Length);
Debug.WriteLine("Received: " + Encoding.ASCII.GetString(data, 0, bytesRead));
stream.Close();
client.Close();
}
}
Udp服务端:
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class UdpServerExample
{
public static void Main()
{
UdpClient udpServer = new UdpClient(8000);
IPEndPoint remoteEP = new IPEndPoint(”127.0.0.1“, 0);
Console.WriteLine("Server is listening on port 8000...");
byte[] data = udpServer.Receive(ref remoteEP);
Console.WriteLine("Received: " + Encoding.ASCII.GetString(data));
byte[] response = Encoding.ASCII.GetBytes("Hello, Client!");
udpServer.Send(response, response.Length, remoteEP);
udpServer.Close();
}
}
UDP客户端:
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class UdpClientExample
{
public static void Main()
{
UdpClient udpClient = new UdpClient();
IPEndPoint remoteEP = new IPEndPoint(”127.0.0.1", 8000);
byte[] message = Encoding.ASCII.GetBytes("Hello, Server!");
udpClient.Send(message, message.Length, remoteEP);
byte[] data = udpClient.Receive(ref remoteEP);
Console.WriteLine("Received: " + Encoding.ASCII.GetString(data));
udpClient.Close();
}
}
上面是基本的网络通信DEMO,TcpClient用于基于连接、可靠的TCP通信,适用于需要数据完整性和可靠传输的场景。Udp用于无连接、不保证传输的UDP通信,适用于对实时性要求高、允许少量数据丢失的场景(如视频流)。会议场景下的传屏软件适合用这个协议,传屏发送端固定帧率一直推送,网络丢失几帧问题不大,重要的是延时低了很多。
TcpClient、UdpClient是位于传输层的通信类,分别实现了基于TCP和UDP协议的通信功能。