1. 串口控制

using System;
using System.IO.Ports;
using System.Windows.Forms;

namespace 串口控制
{
    public partial class Form1 : Form
    {
        //device1
        const byte DeviceOpen1 = 0x01;
        const byte DeviceClose1 = 0x81;
        //device2
        const byte DeviceOpen2 = 0x02;
        const byte DeviceClose2 = 0x82;
        //device3
        const byte DeviceOpen3 = 0x03;
        const byte DeviceClose3 = 0x83;
        //serialport write buffer
        byte[] SerialPortDataBuffer = new byte[1];
        public Form1()
        {
            InitializeComponent();
        }

        //扫描并将串口添加至下拉列表
        private void button1_Click(object sender, EventArgs e)
        {
            SearchAndAddSerialToComboBox(serialPort1, comboBox1);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            SearchAndAddSerialToComboBox(serialPort1, comboBox1);
        }
        //将可用端口号添加到ComboBox
        private void SearchAndAddSerialToComboBox(SerialPort MyPort, ComboBox MyBox)
        {
            //最多容纳20个，太多会影响调试效率
            string Buffer;
            MyBox.Items.Clear();
            for(int i = 1; i < 20; i++)
            {
                try
                {
                    Buffer = "COM" + i.ToString();
                    MyPort.PortName = Buffer;
                    MyPort.Open();//如果失败后面代码不会执行
                    MyBox.Items.Add(Buffer);
                    MyPort.Close();
                }
                catch
                {
                }
            }
            MyBox.SelectedIndex = 0;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                try
                {
                    serialPort1.Close();
                }
                catch
                { }
                button2.Text = "打开串口";
            }
            else
            {
                try
                {
                    serialPort1.PortName = comboBox1.Text;
                    serialPort1.Open();
                    button2.Text = "关闭串口";
                }
                catch
                {
                    MessageBox.Show("串口打开失败", "错误");
                }
            }
        }
        private void WriteByteToSerialPort(byte data)
        {
            byte[] Buffer = new byte[2] { 0x00, data };
            if (serialPort1.IsOpen)
            {
                try
                {
                    serialPort1.Write(Buffer, 0, 2);
                }
                catch
                {
                    MessageBox.Show("串口数据发送出错，请检查", "错误");
                }
            }
            else
            {
                MessageBox.Show("串口未打开，请打开串口", "错误");
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            int i = 0;
            try
            {
                i = Convert.ToInt32(textBox1.Text.Substring(0, textBox1.Text.Length));
            }
            catch
            {
                MessageBox.Show("请输入正确的数字");
                return;
            }
            
            if (serialPort1.IsOpen)
            {
                if(i == 0)
                {
                    return;
                }
                else
                {
                    timer1.Interval = i * 1000;
                    timer1.Start();
                    button3.Enabled = false;
                }
            }
            WriteByteToSerialPort(DeviceOpen1);
        }

        private void button4_Click(object sender, EventArgs e)
        {
            try
            {
                timer1.Stop();//如果定时器没开，则错误处理
            }
            catch
            {

            }
            button3.Enabled = true;
            WriteByteToSerialPort(DeviceClose1);
        }

        private void button5_Click(object sender, EventArgs e)
        {
            WriteByteToSerialPort(DeviceOpen2);
        }

        private void button6_Click(object sender, EventArgs e)
        {
            WriteByteToSerialPort(DeviceClose2);
        }

        private void button7_Click(object sender, EventArgs e)
        {
            WriteByteToSerialPort(DeviceOpen3);
        }

        private void button8_Click(object sender, EventArgs e)
        {
            WriteByteToSerialPort(DeviceClose3);
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            button3.Enabled = true;
            timer1.Stop();
            WriteByteToSerialPort(DeviceClose1);
        }
    }
}

2. 带校验的串口开关控制

using System;
using System.Drawing;
using System.IO.Ports;
using System.Windows.Forms;

namespace ReplyAndControl
{
    public partial class Form1 : Form
    {
        byte DataSended = 0;
        byte[] DataToSend = new byte[] { 0x01, 0x02, 0x03 };
        public Form1()
        {
            InitializeComponent();
            System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = false;
            serialPort1.DataReceived += new SerialDataReceivedEventHandler(SerialPortDataReveived);
        }

        private void SerialPortDataReveived(object sender, SerialDataReceivedEventArgs e)
        {

            byte DataReceived = (byte)(serialPort1.ReadByte());
            //收到数据关闭定时器
            try
            {
                timer1.Stop();
            }
            catch
            {
            }
            SetButtonColor(DataReceived);
        }

        //判断数据校验是否成功
        private void SetButtonColor(int which)
        {
            switch (which)
            {
                case 0x01:
                    button2.BackColor = Color.Green;
                    break;
                case 0x11:
                    button2.BackColor = Color.Red;
                    break;
                case 0x02:
                    button3.BackColor = Color.Green;
                    break;
                case 0x12:
                    button3.BackColor = Color.Red;
                    break;
                case 0x03:
                    button4.BackColor = Color.Green;
                    break;
                case 0x13:
                    button4.BackColor = Color.Red;
                    break;
                case 0x04:
                    button2.BackColor = Color.Green;
                    button3.BackColor = Color.Green;
                    button4.BackColor= Color.Green;
                    break;
                case 0x14:
                    button2.BackColor = Color.Red;
                    button3.BackColor = Color.Red;
                    button4.BackColor = Color.Red;
                    break;
                default:
                    break;
            }
        }

        private void Button_Click(object sender, EventArgs e)
        {
            Button MyButton = (Button)sender;
            DataSended = Convert.ToByte(MyButton.Tag);
            //MyButton.Enabled = false;
            SendDataToSerialPort(serialPort1, DataToSend[DataSended - 1]);
        }

        private void SendDataToSerialPort(SerialPort MyPort, byte DataToSend)
        {
            byte[] DatasToWrite = new byte[] { DataToSend };
            if (serialPort1.IsOpen)
            {
                try
                {
                    MyPort.Write(DatasToWrite, 0, 1);
                    timer1.Interval = 3 * 1000;
                    timer1.Start();
                }
                catch
                {
                    MessageBox.Show("串口数据写入错误", "错误");
                }
            }
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            string MyStr = DataSended.ToString() + "路数据校验超时，请检查";
            timer1.Stop();
            MessageBox.Show(MyStr, "错误");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                try
                {
                    serialPort1.Close();
                }
                catch
                {

                }
                button1.Text = "打开串口";
            }
            else
            {
                try
                {
                    serialPort1.PortName = comboBox1.Text;
                    serialPort1.Open();
                }
                catch
                {
                    MessageBox.Show("串口打开错误，请检查", "错误");
                }
                button1.Text = "关闭窗口";
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string Buffer;
            comboBox1.Items.Clear();
            for (int i = 1; i < 20; i++)
            {
                try
                {
                    Buffer = "COM" + i.ToString();
                    serialPort1.PortName = Buffer;
                    serialPort1.Open();//如果失败后面代码不会执行
                    comboBox1.Items.Add(Buffer);
                    serialPort1.Close();
                }
                catch
                {
                }
            }
            comboBox1.SelectedIndex = 0;
        }
    }
}