c#网络Tcp和udp

TCP 通信

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TCP 服务端

Socket tcpServer = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress ipAddress = new IPAddress(new byte[] { 192, 168, 1, 5 });
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 7788);
tcpServer.Bind(ipEndPoint); // 绑定IP和端口号
tcpServer.Listen(100); // 设置最多有100人连接
Console.WriteLine("开始接客了...");
Socket client = tcpServer.Accept();
Console.WriteLine("一个客户端连接过来了！");// 接收消息
byte[] data = new byte[1024];
int length = client.Receive(data);
string msg = Encoding.UTF8.GetString(data, 0, length);
Console.WriteLine("接收到了客户端的消息：" + msg);// 发送消息
client.Send(Encoding.UTF8.GetBytes("来了，随便坐"));client.Close();
tcpServer.Close();

TCP 客户端

Socket tcpClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress ipAddress = new IPAddress(new byte[] { 192, 168, 1, 5 });
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 7788);
tcpClient.Connect(ipEndPoint);
Console.WriteLine("连接上服务器端了！");// 发送消息
string msg = "我上线了";
tcpClient.Send(Encoding.UTF8.GetBytes(msg));// 接收消息
byte[] data = new byte[1024];
int length = tcpClient.Receive(data);
Console.WriteLine("收到服务器端的消息：" + Encoding.UTF8.GetString(data, 0, length));tcpClient.Close();

TCP 和 UDP 的区别

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• 基于连接（TCP）和无连接（UDP）
• 对系统资源的要求（TCP 较多，UDP 少）
• UDP 程序结构较简单
• 流模式（TCP）与 数据报模式（UDP）
• TCP 保证数据的正确性，UDP 可能丢包
• TCP 保证数据顺序，UDP 不保证

UDP 通信

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UDP 服务端

Socket udpServer = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPAddress ipAddress = new IPAddress(new byte[] { 192, 168, 1, 5 });
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 7788);
udpServer.Bind(ipEndPoint);IPEndPoint ipEndPoint2 = new IPEndPoint(IPAddress.Any, 0);
EndPoint ep = (EndPoint)ipEndPoint2;
byte[] data = new byte[1024];
int length = udpServer.ReceiveFrom(data, ref ep); // 接收数据
Console.WriteLine("接收到数据：" + Encoding.UTF8.GetString(data, 0, length));udpServer.Close();

UDP 客户端

Socket udpClient = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPAddress ipAddress = new IPAddress(new byte[] { 192, 168, 1, 5 });
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 7788);
byte[] data = Encoding.UTF8.GetBytes("您好，客户端上线了！");
udpClient.SendTo(data, ipEndPoint); // 发送数据udpClient.Close();