C# 串口代码

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.IO; using System.IO.Ports;//COM口 申明调用 using System.Collections; using System.Data.OleDb; using System.Diagnostics; namespace V20串口升级 {     public partial class Form1 : Form     {         SerialPort sp =null;         bool isOpen = false;//打开串口标志         bool isSetProperty = false;//属性设置标志         bool isHex = false;//十六进制显示         int numtool = 0;         public Form1()         {           &nbs