一、通訊原理參考https://blog.csdn.net/xiaochenXIHUA/article/details/83446031。

非同步通訊解決同步通訊的缺點可以雙向傳送和接收資訊；非同步通訊思路是引入多執行緒機制，在一個程序中使用兩個執行緒，分別處理接收執行緒與傳送執行緒，這種機制稱為非同步Socket。

二、編寫非同步UDP通訊方法

<1>資訊傳送接收程式碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Test_AsynCommunication
{
    class UDPCommunication
    {
        bool sendingFlag = true;
        bool receiveingFlag = true;
        IPEndPoint iep = null;
        IPEndPoint iep_Receive = null;
        Socket socketClient = null;
        Socket socketServer = null;
        byte[] byteSendingArray = null;
        byte[] byteReceiveArray = null;


        static void Main(string[] args)
        {
            UDPCommunication obj = new UDPCommunication();
            Console.WriteLine("---非同步通訊，A---");
            obj.OpenSendAndReceiveThread();
        }

        /// <summary>
        /// 分別開啟“接收”與“傳送”執行緒
        /// </summary>
        private void OpenSendAndReceiveThread()
        {
            Thread thSending = new Thread(SendingData);
            Thread thReveive = new Thread(ReceiveData);
            thSending.Start();
            thReveive.Start();
        }

        /// <summary>
        /// 傳送執行緒的方法
        /// </summary>
        private void SendingData()
        {
            Thread.Sleep(500);//休眠0.5秒
            if (sendingFlag)
            {
                byteSendingArray = new byte[100];

                //定義網路地址
                iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"),1002);
                socketClient = new Socket(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp);
                sendingFlag = false;
            }
            //傳送資料
            Console.WriteLine("請輸入傳送的資料：");
            EndPoint ep = (EndPoint)iep;
            while (true)
            {
                string strMsg = Console.ReadLine();
                //位元組轉換
                byteSendingArray = Encoding.Default.GetBytes(strMsg);
                socketClient.SendTo(byteSendingArray,ep);
                if (strMsg=="exit")
                {
                    break;
                }
            }
            socketClient.Shutdown(SocketShutdown.Both);
            socketClient.Close();
        }

        /// <summary>
        /// 接收執行緒的方法
        /// </summary>
        private void ReceiveData()
        {
            if (receiveingFlag)
            {
                byteReceiveArray = new byte[100];

                iep_Receive = new IPEndPoint(IPAddress.Parse("127.0.0.1"),1001);
                socketServer = new Socket(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp);
                socketServer.Bind(iep_Receive);
                receiveingFlag = false;
            }
            //接受收據
            EndPoint ep = (EndPoint)iep_Receive;
            while(true)
            {
                int intReceiveLenght = socketServer.ReceiveFrom(byteReceiveArray,ref ep);
                string strReceiveStr = Encoding.Default.GetString(byteReceiveArray,0,intReceiveLenght);
                Console.WriteLine(strReceiveStr);
            }

        }

    }//class_end
}
 

<2>資訊傳送接收程式碼 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Test_AsynCommunicationB
{
    class UDPCommunication
    {
        bool sendingFlag = true;
        bool receiveingFlag = true;
        IPEndPoint iep = null;
        IPEndPoint iep_Receive = null;
        Socket socketClient = null;
        Socket socketServer = null;
        byte[] byteSendingArray = null;
        byte[] byteReceiveArray = null;


        static void Main(string[] args)
        {
            UDPCommunication obj = new UDPCommunication();
            Console.WriteLine("---非同步通訊，B---");
            obj.OpenSendAndReceiveThread();
        }

        /// <summary>
        /// 分別開啟“接收”與“傳送”執行緒
        /// </summary>
        private void OpenSendAndReceiveThread()
        {
            Thread thSending = new Thread(SendingData);
            Thread thReveive = new Thread(ReceiveData);
            thSending.Start();
            thReveive.Start();
        }

        /// <summary>
        /// 傳送執行緒的方法
        /// </summary>
        private void SendingData()
        {
            Thread.Sleep(500);//休眠0.5秒
            if (sendingFlag)
            {
                byteSendingArray = new byte[100];

                //定義網路地址
                iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 1001);
                socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
                sendingFlag = false;
            }
            //傳送資料
            Console.WriteLine("請輸入傳送的資料：");
            EndPoint ep = (EndPoint)iep;
            while (true)
            {
                string strMsg = Console.ReadLine();
                //位元組轉換
                byteSendingArray = Encoding.Default.GetBytes(strMsg);
                socketClient.SendTo(byteSendingArray, ep);
                if (strMsg == "exit")
                {
                    break;
                }
            }
            socketClient.Shutdown(SocketShutdown.Both);
            socketClient.Close();
        }

        /// <summary>
        /// 接收執行緒的方法
        /// </summary>
        private void ReceiveData()
        {
            if (receiveingFlag)
            {
                byteReceiveArray = new byte[100];

                iep_Receive = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 1002);
                socketServer = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
                socketServer.Bind(iep_Receive);
                receiveingFlag = false;
            }
            //接受收據
            EndPoint ep = (EndPoint)iep_Receive;
            while (true)
            {
                int intReceiveLenght = socketServer.ReceiveFrom(byteReceiveArray, ref ep);
                string strReceiveStr = Encoding.Default.GetString(byteReceiveArray, 0, intReceiveLenght);
                Console.WriteLine(strReceiveStr);
            }

        }

    }//class_end
}
 

三、執行測試

 注：本內容來自《Unity3D/2D遊戲開發從0到1》28章