C# SerialPort触发两次事件

 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;


namespace VoltagePort
{
    public partial class Form1 : Form
    {
        int vol = 0;
        Hex hex = new Hex();
        DecimalToBinary dtb = new DecimalToBinary();
        public delegate void DataReceivedDelegate();
        //十六进制值
        byte[] bHex = new byte[]{0x00,0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
                        0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
                        0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x20,
                        0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40,
                        0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
                        0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60,
                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
                        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80,
                        0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90,
                        0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0,
                        0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0,
                        0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0,
                        0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0,
                        0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0,
                        0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0,
                        0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
        };

        public Form1()
        {
            InitializeComponent();
        }

        //打开端口&关闭端口
        private void btnOpenPort_Click(object sender, EventArgs e)
        {
            //判断按钮的状态
            if (btnOpenPort.Text.Equals("关闭端口"))
            {
                serialPort.Close();
                btnOpenPort.Text = "打开端口";
                return;
            }
            string portname = cmbPort.Text;//端口号

            if (portname.Equals(""))
            {
                MessageBox.Show("请选择COM端口!", "系统提示");
                return;
            }

            serialPort.BaudRate = 9600;
            serialPort.PortName = portname;
            serialPort.StopBits = System.IO.Ports.StopBits.One;
            serialPort.DataBits = 8;
            serialPort.ReceivedBytesThreshold = 3;

           

            try
            {
                serialPort.Open();
                serialPort.DiscardInBuffer();
            }
            catch (Exception ex)
            {
                MessageBox.Show(portname + "端口不存在", "系统提示");
                return;
            }

            btnOpenPort.Text = "关闭端口";
        }

        //端口号的下拉菜单
        private void cmbPort_Click(object sender, EventArgs e)
        {
            cmbPort.Items.Clear();
            for (int i = 1; i <= 10; i++)
            {
                cmbPort.Items.Add("COM" + i);
            }
        }

        //当窗口关闭的同时关闭端口
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            serialPort.Close();
        }

        //电池地址码下拉框
        private void cmbVolNum_Click(object sender, EventArgs e)
        {
            cmbVolNum.Items.Clear();
            for (int i = 1; i <= 256; i++)
            {
                cmbVolNum.Items.Add(i);
            }
        }

        //电池的地址码下拉框
        private void cmbVolAddress_Click(object sender, EventArgs e)
        {
            cmbVolAddress.Items.Clear();
            for (int i = 1; i < 257; i++)
            {
                cmbVolAddress.Items.Add(i);
            }

        }

        //测试电池电压、温度、内阻
        private void btnTest_Click(object sender, EventArgs e)
        {
            //判断端口是否打开状态
            if (serialPort.IsOpen == false)
            {
                MessageBox.Show("COM端口没有打开!", "系统提示");
                return;
            }

            //获取电池的编号
            String volNum = cmbVolNum.Text;
            if (volNum.Equals(""))
            {
                MessageBox.Show("测试项的电池编号不能为空!", "系统提示");
                return;
            }
            vol = Int32.Parse(volNum);

            //获取测试项目(电压、温度、内阻)

            //如果选中 radRes 测试内阻
            if (radRes.Checked)
            {
                byte[] byteImp = new byte[3];
                byteImp[0] = bHex[vol];
                byteImp[1] = 0x62;
                byte imp = (byte)(bHex[vol] ^ 0x62);
                byteImp[2] = imp;
                serialPort.Write(byteImp, 0, 3);
            }

            //如果选中 radTem 测试温度
            if (radTem.Checked)
            {
                byte[] byteTem = new byte[3];
                byteTem[0] = bHex[vol];
                byteTem[1] = 0x61;
                byte tem = (byte)(bHex[vol] ^ 0x61);
                byteTem[2] = tem;
                serialPort.Write(byteTem, 0, byteTem.Length);
            }

            //如果选中 radVol 测试电压
            if (radVol.Checked)
            {
                byte[] byteVol = new byte[3];
                byteVol[0] = bHex[vol];
                byteVol[1] = 0x60;
                byte xor = (byte)(bHex[vol] ^ 0x60);//byteVol[0]异或byteVol[1]
                byteVol[2] = xor;
                serialPort.Write(byteVol, 0, byteVol.Length);

                //System.Threading.Thread.Sleep(100);//写完数据后必须要睡上一段时间,否则读到得数据不全或者过多。(出现数据错位的情况)
                ////inceptData();//调用读取串口数据的方法
                //MessageBox.Show(serialPort.BytesToRead+"");
            }
           
        }

        //发送地址码
        private void btnSend_Click(object sender, EventArgs e)
        {
            string address = cmbVolAddress.Text;
            if (address.Equals(""))
            {
                MessageBox.Show("设置通信地址项的电池编号不能为空!", "系统提示");
                return;
            }
            string volAddress = hex.DtoX(Int32.Parse(address));
            MessageBox.Show(volAddress);
        }

        //ListView 控件

        public void addListView(string data, string result)
        {
            //获取当前时间
            string time = System.DateTime.Now.ToLocalTime().ToString();

            lvwResult.View = View.Details;
            lvwResult.FullRowSelect = true;

            ListViewItem item = new ListViewItem(vol + "");
            item.SubItems.Add(time);
            item.SubItems.Add(data);
            item.SubItems.Add(result);
            lvwResult.Items.Add(item);
        }

        //清楚lvwResult里面的数据
        private void btnClearWindows_Click(object sender, EventArgs e)
        {
            lvwResult.Items.Clear();
        }

        //读取串口的数据
        public void inceptData()
        {
            int i = 0;
            string b1 = "";
            string b2 = "";
            string msg = "";
            string s = serialPort.ReadExisting();
            foreach (char c in s)
            {

                i++;
                int n = (int)c;
                msg += n.ToString("X2") + ",";//X2表示16进制(暂时这么理解)x有大小写区分2表示两位2表示位数

                if (i == 2)
                {
                    b1 = dtb.DtoB(n);
                }
                if (i == 3)
                {
                    b2 = dtb.DtoB(n);
                }
            }
            while (b1.Length < 8)
            {
                b1 = 0 + b1;
            }
            while (b2.Length < 8)
            {
                b2 = 0 + b2;
            }
            double res = result(b1, b2);
            addListView(msg, res + "");
            return;
        }


        //解码结果
        public double result(string b1, string b2)
        {
            double value = 0;
            string msg = "";
            string b = "";
            b = b1 + b2;
            string exp = b.Trim().Substring(1, 4);//指数
            string man = b.Trim().Substring(4);//尾数

            int bit10 = Convert.ToInt32(man.Trim().Substring(1, 1));
            int bit9 = Convert.ToInt32(man.Trim().Substring(2, 1));
            int bit8 = Convert.ToInt32(man.Trim().Substring(3, 1));
            int bit7 = Convert.ToInt32(man.Trim().Substring(4, 1));
            int bit6 = Convert.ToInt32(man.Trim().Substring(5, 1));
            int bit5 = Convert.ToInt32(man.Trim().Substring(6, 1));
            int bit4 = Convert.ToInt32(man.Trim().Substring(7, 1));
            int bit3 = Convert.ToInt32(man.Trim().Substring(8, 1));
            int bit2 = Convert.ToInt32(man.Trim().Substring(9, 1));
            int bit1 = Convert.ToInt32(man.Trim().Substring(10, 1));
            int bit0 = Convert.ToInt32(man.Trim().Substring(11, 1));

            double dBit10 = 0, dBit9 = 0, dBit8 = 0, dBit7 = 0, dBit6 = 0, dBit5 = 0, dBit4 = 0, dBit3 = 0, dBit2 = 0, dBit1 = 0, dBit0 = 0;

            if (bit10 != 0)
            {
                dBit10 = Math.Pow(2, -1);
            }
            else
            {
                dBit10 = 0;
            }

            if (bit9 != 0)
            {
                dBit9 = Math.Pow(2, -2);
            }
            else
            {
                dBit9 = 0;
            }

            if (bit8 != 0)
            {
                dBit8 = Math.Pow(2, -3);
            }
            else
            {
                dBit8 = 0;
            }

            if (bit7 != 0)
            {
                dBit7 = Math.Pow(2, -4);
            }
            else
            {
                dBit7 = 0;
            }

            if (bit6 != 0)
            {
                dBit6 = Math.Pow(2, -5);
            }
            else
            {
                dBit6 = 0;
            }

            if (bit5 != 0)
            {
                dBit5 = Math.Pow(2, -6);
            }
            else
            {
                dBit5 = 0;
            }

            if (bit4 != 0)
            {
                dBit4 = Math.Pow(2, -7);
            }
            else
            {
                dBit4 = 0;
            }

            if (bit3 != 0)
            {
                dBit3 = Math.Pow(2, -8);
            }
            else
            {
                dBit3 = 0;
            }

            if (bit2 != 0)
            {
                dBit2 = Math.Pow(2, -9);
            }
            else
            {
                dBit2 = 0;
            }

            if (bit1 != 0)
            {
                dBit1 = Math.Pow(2, -10);
            }
            else
            {
                dBit1 = 0;
            }

            if (bit0 != 0)
            {
                dBit0 = Math.Pow(2, -11);
            }
            else
            {
                dBit0 = 0;
            }

            double intMan = 1.0 + dBit10 + dBit9 + dBit8 + dBit7 + dBit6 + dBit5 + dBit4 + dBit3 + dBit2 + dBit1 + dBit0;
            //将二进制的数转换为十进制的数,
            int intExp = Convert.ToInt32(exp, 2);

            //判断
            if (1 <= intExp && intExp <= 14)
            {
                value = Math.Pow(2, intExp - 7) * intMan;
            }
            if (intExp == 0 && intMan != 0)
            {
                value = Math.Pow(2, intExp - 6) * intMan;
            }
            if (intExp == 0 && intMan == 0)
            {
                value = 0;
            }
            if (intExp == 15 && intMan == 0)
            {
                msg = "无限大";
            }
            if (intExp == 15 && intMan != 0)
            {
                msg = "没有此地址";
            }
            serialPort.DiscardOutBuffer();
            return value;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            serialPort.DataReceived += new SerialDataReceivedEventHandler(serialPort_DataReceived);
        }
        void serialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            Invoke(new DataReceivedDelegate(inceptData), new object[] { });
        }
    }
}

 

 

 

 

 

using System;
using System.Collections.Generic;
using System.Text;

namespace VoltagePort
{
    class Hex
    {
        //十进制转十六进制
        public string DtoX(int d)
        {
            string x = "";
            if (d < 16)
            {
                x = chang(d);
            }
            else
            {
                int c;

                int s = 0;
                int n = d;
                int temp = d;
                while (n >= 16)
                {
                    s++;
                    n = n / 16;
                }
                string[] m = new string[s];
                int i = 0;
                do
                {
                    c = d / 16;
                    m[i++] = chang(d % 16);//判断是否大于10,如果大于10,则转换为A~F的格式
                    d = c;
                } while (c >= 16);
                x = chang(d);
                for (int j = m.Length - 1; j >= 0; j--)
                {
                    x += m[j];
                }
            }
            return x;
        }
        //判断是否为10~15之间的数,如果是则进行转换
        public string chang(int d)
        {
            string x = "";
            switch (d)
            {
                case 10:
                    x = "A";
                    break;
                case 11:
                    x = "B";
                    break;
                case 12:
                    x = "C";
                    break;
                case 13:
                    x = "D";
                    break;
                case 14:
                    x = "E";
                    break;
                case 15:
                    x = "F";
                    break;
                default:
                    x = d.ToString();
                    break;
            }
            return x;
        }
    }
}

 

 

 

using System;
using System.Collections.Generic;
using System.Text;

//十进制转换成二进制

namespace VoltagePort
{
    public class DecimalToBinary
    {
        //十进制转换成二进制
        public string DtoB(int d)
        {
            string b = "";
            //判断该数如果小于2,则直接输出
            if (d < 2)
            {
                b = d.ToString();
            }
            else
            {
                int c;
                int s = 0;
                int n = d;
                while (n >= 2)
                {
                    s++;
                    n = n / 2;
                }
                int[] m = new int[s];
                int i = 0;
                do
                {
                    c = d / 2;
                    m[i++] = d % 2;
                    d = c;
                } while (c >= 2);
                b = d.ToString();
                for (int j = m.Length - 1; j >= 0; j--)
                {
                    b += m[j].ToString();
                }
            }
            return b;
        }
    }
}

<think>嗯,用户在使用C#SerialPort类时遇到了BytesToRead属性的错误。首先,我需要理解这个问题可能的原因。根据用户提供的引用内容,特别是引用[1]提到每次读取总是只有8个字节,而缓冲区是20字节的。这可能涉及到数据接收不完整或者同步问题。 接下来,用户还提到了引用[4]中的情况,当有大量线程池操作时,可能导致信号丢失,猜测是线程池资源竞争的问题。所以,可能的问题根源包括数据接收不完整、事件处理机制不当,或者多线程同步的问题。 我需要回顾SerialPort类的基本用法。通常,使用DataReceived事件来异步读取数据,但该事件是在辅助线程触发的,需要注意跨线程访问UI组件的问题。另外,BytesToRead属性返回的是接收缓冲区中当前的字节数,可能在事件触发时数据还未完全到达,导致读取不完整。 可能的解决方案包括: 1. 确保在DataReceived事件中使用ReadExisting或Read方法时,正确读取所有可用字节,可能需要循环读取直到BytesToRead为0。 2. 检查是否在事件处理中进行了耗时操作,导致后续事件被阻塞,应该将数据处理移到其他线程或使用缓冲区队列。 3. 处理多线程同步,避免同时访问串口资源导致的竞争条件。 4. 检查串口配置是否正确,比如波特率、数据位、停止位等,硬件流控制是否启用,可能影响数据传输的稳定性。 此外,引用[3]提到Remon的串口类经过多年改进,可能用户可以考虑使用这个经过优化的第三方库,避免微软SerialPort类的一些潜在问题。 用户的问题可能具体表现为读取的字节数不符合预期,比如每次只能读取8字节,而期望读取更多。这可能是因为数据到达的速度和事件触发的频率不一致,或者缓冲区设置的问题。需要确保在事件处理中尽可能快地读取数据,避免缓冲区溢出或数据残留。 另外,需要检查是否在打开串口前正确配置了端口参数,比如ReadBufferSize是否足够大,以及是否有可能因为硬件或驱动程序的问题导致数据接收不完整。 最后,用户可能需要实现一个稳定的数据接收机制,比如使用自定义缓冲区,在DataReceived事件中不断追加数据,直到满足某个条件(如特定结束符)才进行完整处理,避免依赖单次读取的字节数。</think>### C# SerialPort.BytesToRead属性问题解决方案 #### 问题分析 当使用`SerialPort.BytesToRead`属性时出现错误,通常表现为以下现象: - 数据接收不完整(如引用[1]描述的固定读取8字节) - 线程竞争导致信号丢失(引用[4]描述的密集线程池场景) - 事件响应延迟或遗漏 #### 解决步骤 1. **基础事件处理优化** ```csharp private void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e) { // 使用临时缓冲区读取 byte[] buffer = new byte[serialPort.BytesToRead]; serialPort.Read(buffer, 0, buffer.Length); // 使用委托更新UI(避免跨线程访问) this.BeginInvoke((MethodInvoker)delegate { textBox.AppendText(Encoding.ASCII.GetString(buffer)); }); } ``` *注意:`Read()`方法会清空接收缓冲区,避免数据残留[^3]* 2. **线程同步强化** ```csharp private readonly object _lock = new object(); void comport_PinChanged(object sender, SerialPinChangedEventArgs e) { lock (_lock) // 加锁保证线程安全 { if (e.EventType == SerialPinChange.CDChanged) { // 处理硬件信号变化 } } } ``` 3. **缓冲区动态管理** ```csharp private List<byte> _globalBuffer = new List<byte>(); void DataReceivedHandler(object sender, SerialDataReceivedEventArgs e) { int bytesToRead = serialPort.BytesToRead; byte[] buffer = new byte[bytesToRead]; serialPort.Read(buffer, 0, bytesToRead); _globalBuffer.AddRange(buffer); // 全局缓冲区累积 while (_globalBuffer.Count >= 20) // 按协议处理完整数据包 { ProcessPacket(_globalBuffer.Take(20).ToArray()); _globalBuffer.RemoveRange(0, 20); } } ``` 4. **底层参数调优** ```csharp serialPort.ReadBufferSize = 4096; // 增大接收缓冲区 serialPort.Handshake = Handshake.RequestToSend; // 启用硬件流控制 serialPort.ReceivedBytesThreshold = 10; // 设置触发阈值 ``` #### 关键建议 1. 避免在事件处理中直接操作UI控件(使用`BeginInvoke`跨线程更新) 2. 对共享资源(如缓冲区)使用`lock`关键字进行线程同步 3. 采用第三方优化库(如引用[3]提到的Remon串口类) 4. 硬件层面检查信号质量(引用[4]的线程池竞争问题需排查硬件响应) #### 高级调试技巧 ```csharp // 在读取前添加状态检查 if (serialPort.IsOpen && serialPort.BytesToRead > 0) { // 读取操作 } // 使用超时保护 serialPort.ReadTimeout = 500; // 设置500ms超时 ```
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