C# 完整的通信代码（点对点，点对多，同步，异步，UDP，TCP

//字符串与字节数组相互转换

data = Encoding .ASCII .GetBytes (welcome );

//发送信息

newsock .SendTo (data ,data.Length ,SocketFlags .None ,Remote );

while (true )

{

data =new byte [1024];

//发送接受信息

recv =newsock.ReceiveFrom(data ,ref Remote);

Console .WriteLine (Encoding .ASCII .GetString (data ,0,recv));

newsock .SendTo (data ,recv ,SocketFlags .None ,Remote );

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net;

using System.Net.Sockets;

namespace UDPClient

{

class Program

{

static void Main(string[] args)

{

//定义网络类型，数据连接类型和网络协议UDP

Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

string welcome = "Hello! ";

data = Encoding.ASCII.GetBytes(welcome);

server.SendTo(data, data.Length, SocketFlags.None, ipep);

IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);