C# 串口扫描枪读取数据的实现

/// <summary>
    /// 扫描枪（串口 ）工作类
    /// </summary>
    public class commbar : idisposable
    {
        /// <summary>
        /// 串口引用
        /// </summary>
        public serialport serialport;

        /// <summary>
        /// 存储转换的数据值
        /// </summary>
        public string code { get; set; }

        /// <summary>
        /// 扫描枪（串口 ）工作类
        /// </summary>
        public commbar()
        {
            serialport = new serialport();
        }

        /// <summary>
        /// 串口状态
        /// </summary>
        public bool isopen
        {
            get
            {
                return serialport.isopen;
            }
        }

        /// <summary>
        /// 打开串口
        /// </summary>
        /// <returns></returns>
        public bool open()
        {
            if (serialport.isopen)
            {
                close();
            }
            serialport.open();
            if (serialport.isopen)
            {
                return true;
            }
            else
            {
                messagebox.show("串口打开失败！");
                return false;
            }
        }

        /// <summary>
        /// 关闭串口
        /// </summary>
        public void close()
        {
            serialport.close();
        }

        /// <summary>
        /// 写入数据
        /// </summary>
        /// <param name="send">数据</param>
        /// <param name="offset">偏移量</param>
        /// <param name="count">字节数</param>
        public void writeport(byte[] send, int offset, int count)
        {
            if (isopen)
            {
                serialport.write(send, offset, count);
            }
        }

        /// <summary>
        /// 获取可用串口
        /// </summary>
        /// <returns>串口名称列表</returns>
        public string[] getcomname()
        {
            string[] names = null;
            try
            {
                names = serialport.getportnames(); // 获取所有可用串口的名字
            }
            catch (exception)
            {
                system.windows.forms.messagebox.show("找不到串口");
            }
            return names;
        }

        /// <summary>
        /// 注册一个串口
        /// </summary>
        /// <param name="portname">端口号</param>
        /// <param name="baudrate">波特率</param>
        public void serialportvalue(string portname, int baudrate)
        {
            //串口名
            serialport.portname = portname;
            //波特率
            serialport.baudrate = baudrate;
            //数据位
            serialport.databits = 8;
            //两个停止位
            serialport.stopbits = system.io.ports.stopbits.one;
            //无奇偶校验位
            serialport.parity = system.io.ports.parity.none;
            serialport.readtimeout = 100;
            //commbar.serialport.writetimeout = -1;
        }

        #region 实现idisposable

        private bool m_disposed = false;//标识资源是否被释放过

        /// <summary>
        /// 释放
        /// </summary>
        public void dispose()
        {
            dispose(true);
            gc.suppressfinalize(this);//防止finalize调用
        }

        /// <summary>
        /// 释放
        /// </summary>
        /// <param name="disposing"></param>
        protected virtual void dispose(bool disposing)
        {
            if (!m_disposed)
            {
                if (disposing)
                {
                    //释放托管资源
                    serialport.close();
                }
                //释放非托管资源
                m_disposed = true;
            }
        }

        /// <summary>
        /// 析构函数
        /// </summary>
        ~commbar()
        {
            dispose(false);
        }

        #endregion
    }

commbar commbar;
        public form2()
        {
          initializecomponent();
            commbar = new commbar();
            //注册一该串口
            commbar.serialportvalue("com1", 9600);
            //打开串口
            if (commbar.open())
                //关联事件处理程序
                commbar.serialport.datareceived += new system.io.ports.serialdatareceivedeventhandler(serialport_datareceived);
        }

//委托，指向codetext方法
        private delegate void modifybutton_dg(commbar commbar);

        //串口接收接收事件处理程序
        //每当串口讲到数据后激发
        void serialport_datareceived(object sender, system.io.ports.serialdatareceivedeventargs e)
        {
            system.threading.thread.sleep(100);
            byte[] m_recvbytes = new byte[commbar.serialport.bytestoread];//定义缓冲区大小
            int result = commbar.serialport.read(m_recvbytes, 0, m_recvbytes.length);//从串口读取数据
            if (result <= 0)
                return;
            commbar.code = encoding.ascii.getstring(m_recvbytes, 0, m_recvbytes.length);//对数据进行转换
            this.invoke(new modifybutton_dg(codetext), commbar);//调用委托，将值传给文本框
            commbar.serialport.discardinbuffer();
        }

//用来为文本框赋值
        private void codetext(commbar commbar)
        {
          //加逻辑判断等
            this.txt_asn.text = commbar.code;
               
        }

this.lbl_error.text = "asn码已存在！";
  this.lbl_error.visible = true;
  system.threading.tasks.task.delay(3000).continuewith(_ =>
   {
      invoke(new methodinvoker(() => {
      lbl_error.visible = false;

       }));
   });