项目介绍：
本实例主要是接收安检闸机的数据解析并显示到界面上，只做功能实现，不做界面美化
硬件：闸机一个、网线一根、电脑主机
开发环境：vs2017 系统：win10
涵盖知识点：tcp通讯、文件写入、多线程，委托、类型转换等

软件操作流程：

点击开始监听按钮，8999要是未被占用则开启监听，然后人刷身份证通过安检闸机就可以接收到数据

数据格式截图：

安检闸机图片：

知识点介绍： 
1. socket.Listen(10); 官方给出的解释：挂起连接队列的最大长度。 连接队列，即连接池，也就是要保证挂起的连接池中至少要有10个连接                我解释一下，为什么要提前准备10个挂起的连接，原因就是每当一个新用户接入进来时，就需要立即创建一个socket，创建也需要时间和消耗系统资源，这样就会影响高并发的性能                ，用不用，先放那，用的时候直接取即

2. Socket clientSocket = socket.Accept();

AcceptSocket是同步的，你可以用异步通讯的BeginAcceptSocket或者用多线程。没有请求到达，就会“卡”住，术语叫程序阻塞，socket同步通讯就是这个步骤，执行到AcceptSocket就会阻塞等待请求，直到有请求到达时，才执行后面的语句，并且处理这个请求

3. while (true) 因为组要一直监听，所以得死循环；

4. 开启一个后来线程，不然主界面会假死 new Thread(delegate ()            {主体代码;})            { IsBackground = true }.Start();
5.从其它线程访问主线程控件需要委托，不然界面不会有数据的 this.Invoke((EventHandler)delegate                        {                            richTextBox1.Text += “”；                        });


完整代码如下：

using System;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Windows.Forms;
using System.IO;
using System.Threading;
using System.Text;
using System.Drawing;namespace TcpRecive
{public partial class mainForm : Form{public mainForm(){InitializeComponent();}private void Form1_Load(object sender, EventArgs e){textBox1.Text = "8999"; }public void tcpRecive(int port){if (PortIsUse(port)){label1.Text = "端口" + port.ToString() + "被占用"; return;}else label1.Text = "端口" + port.ToString() + "没有占用,监听已开启";new Thread(delegate (){int recv;//定义接收数据长度变量//IPAddress ip = IPAddress.Parse("192.168.1.119");//接收端所在IP 192.168.1.119换成127.0.0.1不可以为什么？IPEndPoint ipEnd = new IPEndPoint(IPAddress.Any, port);//接收端所监听的接口,ip也可以用IPAddress.AnySocket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//初始化一个Socket对象socket.Bind(ipEnd);//绑定套接字到一个IP地址和一个端口上(bind())；//官方给出的解释：挂起连接队列的最大长度。//连接队列，即连接池，也就是要保证挂起的连接池中至少要有10个连接//我解释一下，为什么要提前准备10个挂起的连接，原因就是每当一个新用户接入进来时，就需要立即创建一个socket，创建也需要时间和消耗系统资源，这样就会影响高并发的性能//，用不用，先放那，用的时候直接取即可socket.Listen(10);while (true){try{byte[] data = new byte[70000];//对data清零Socket clientSocket = socket.Accept(); //一旦接受连接，创建一个客户端recv = clientSocket.Receive(data);// 或者clientSocket.Receive(data, data.Length, SocketFlags.None);获取收到的数据的长度if (recv == 0) //如果收到的数据长度小于0，则退出break;//string stringData = Encoding.ASCII.GetString(data);string stringData = Encoding.UTF8.GetString(data);dataDecode(data);fileWrite(DateTime.Now.ToString("yy-MM-dd hh:mm:ss") + "\n" + stringData);}catch(Exception ex){MessageBox.Show(ex.ToString());}}}){ IsBackground = true }.Start();}/// <summary>/// 字节数组转16进制字符串/// </summary>/// <param name="bytes"></param>/// <returns></returns>public static string byteToHexStr(byte[] bytes){string returnStr = "";if (bytes != null){for (int i = 0; i < bytes.Length; i++){returnStr += bytes[i].ToString("X2");}}return returnStr;}public void dataDecode(byte[] data){int dataL = 0, isPass = 0, nameL = 0, ethnicL = 0, sexL = 0, birthdayL = 0, adressL = 0, cardNoL = 0, startTimeL = 0, endTimeL = 0, cardImageL = 0, captureImageL = 0;string item = "", name = "", ethnic = "", sex = "", birthday = "", adress = "", cardNo = "", startTime = "", endTime = "";dataL = BitConverter.ToInt32(data, 0);//数据包大小，低字节在前面，高字节在后面isPass = BitConverter.ToInt32(data, 4);//人证核验结果nameL = BitConverter.ToInt32(data, 8);//姓名长度name = Encoding.UTF8.GetString(data, 12, nameL);//姓名ethnicL = BitConverter.ToInt32(data, 12 + nameL);//民族长度ethnic = Encoding.UTF8.GetString(data, 16 + nameL, ethnicL);//民族sexL = BitConverter.ToInt32(data, 16 + nameL + ethnicL);//性别长度sex = Encoding.UTF8.GetString(data, 20 + nameL+ ethnicL,sexL);//性别birthdayL = BitConverter.ToInt32(data, 20 + nameL + ethnicL + sexL);birthday = Encoding.UTF8.GetString(data, 24 + nameL + ethnicL+sexL,birthdayL);//出生日期adressL = BitConverter.ToInt32(data, 24 + nameL + ethnicL + sexL + birthdayL);adress = Encoding.UTF8.GetString(data, 28 + nameL + ethnicL + sexL+birthdayL, adressL);//地址cardNoL = BitConverter.ToInt32(data, 28 + nameL + ethnicL + sexL + birthdayL + adressL);cardNo = Encoding.UTF8.GetString(data, 32 + nameL + ethnicL + sexL + birthdayL+adressL, cardNoL);//身份证号码startTimeL = BitConverter.ToInt32(data, 32 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL);startTime = Encoding.UTF8.GetString(data, 36 + nameL + ethnicL + sexL + birthdayL + adressL+ cardNoL, startTimeL);//身份证起始时间endTimeL = BitConverter.ToInt32(data, 36 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL);endTime = Encoding.UTF8.GetString(data, 40 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL+ startTimeL, endTimeL);//身份证终止时间if (isPass == 1)item = "人证核验:成功" + "\n姓名：" + name + "\n民族：" + ethnic + "\n性别：" + sex + "\n出生日期：" + birthday +"\n地址：" + adress + "\n身份证号码：" + cardNo + "\n身份证起始时间：" + startTime + "\n身份证终止时间：" + endTime;elseitem = "人证核验:失败" + "\n姓名：" + name + "\n民族：" + ethnic + "\n性别：" + sex + "\n出生日期：" + birthday +"\n地址：" + adress + "\n身份证号码：" + cardNo + "\n身份证起始时间：" + startTime + "\n身份证终止时间：" + endTime;cardImageL = BitConverter.ToInt32(data, 40 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL + endTimeL);MemoryStream ms1 = new MemoryStream(data, 44 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL + endTimeL, cardImageL);captureImageL = BitConverter.ToInt32(data, 44 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL + endTimeL + cardImageL);MemoryStream ms2 = new MemoryStream(data, 48 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL + endTimeL+cardImageL, captureImageL);//ms.Write(data, 44 + nameL + ethnicL + sexL + birthdayL + adressL + cardNoL + startTimeL + endTimeL, cardImageL);Image img1 = Image.FromStream(ms1);Image img2 = Image.FromStream(ms2);this.Invoke((EventHandler)delegate{richTextBox1.Text = item;pictureBox1.Image = img1; //更新在窗体控件上          pictureBox2.Image = img2;});ms1.Flush(); ms2.Flush();ms1.Close(); ms2.Close();ms1.Dispose(); ms2.Dispose();}public void fileWrite(string str){if (!File.Exists("info.txt"))File.Create("info.txt").Close();//创建文件并关闭StreamWriter sw = new StreamWriter("info.txt",true);//向文件追加数据sw.WriteLine(str);sw.Close();}//通过 IPGlobalProperties来获取本机的网络连接的信息，并通过GetActiveTcpListeners找到已用端口，进而可以知道所需的端口是否已被占用public static bool PortIsUse(int port){bool isUse = false;IPGlobalProperties ipProperties = IPGlobalProperties.GetIPGlobalProperties();IPEndPoint[] ipEndPoints = ipProperties.GetActiveTcpListeners();//找到已用端口foreach (IPEndPoint endPoint in ipEndPoints){if (endPoint.Port == port)//判断是否存在{isUse= true;break;}}return isUse;}private void button1_Click(object sender, EventArgs e){tcpRecive(int.Parse(textBox1.Text));}}
}

运行结果：