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1. 实现一个简单的倒计时器开始、暂停

namespace Timer
{public partial class Form1 : Form{int count;//用于定时器计数int time;//存储设定的定时值bool parse = false;//控制暂停计时public Form1(){InitializeComponent();}//窗口创建初始化函数private void Form1_Load(object sender, EventArgs e){//双击窗体后在这里给下拉框添加或者在属性items里添加都可以for(int i = 1; i < 100; i++){comboBox1.Items.Add(i.ToString() + "秒");}comboBox1.Text = "1秒";}private void timer1_Tick(object sender, EventArgs e){count++;//记录、当前秒label3.Text = (time - count).ToString() + "秒";//显示剩余时间progressBar1.Value = count;//设置进度条进度if(count == time){timer1.Stop();//时间到，停止计时System.Media.SystemSounds.Asterisk.Play();//提示音MessageBox.Show("时间到，停止计时","提示");//弹出提示框count = 0;progressBar1.Value = 0;comboBox1.Text = null;}}//开始计时按钮事件private void button1_Click(object sender, EventArgs e){if (parse == true){parse = false;timer1.Stop();return;}string str = comboBox1.Text; //将下拉框内容添加到一个变量中time = Convert.ToInt16(str.Substring(0,str.Length - 1)); //得到设定的定时值progressBar1.Maximum = time;//进度条最大数值parse = true;timer1.Start();//开始计时}}
}

2. 串口助手开发

创建项目的时候要选带（.NET Framework）的窗体应用

using System;
using System.IO.Ports;
using System.Text;
using System.Windows.Forms;namespace SerialCommunicate
{public partial class Form1 : Form{public Form1(){InitializeComponent();//串口数据接收事件serialPort1.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);//串口接收编码serialPort1.Encoding = Encoding.GetEncoding("UTF-8");System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = false;}private void Form1_Load(object sender, EventArgs e){for(int i = 1; i < 20; i++){comboBox1.Items.Add("COM" + i.ToString());}comboBox1.Text = "COM1";comboBox2.Text = "4800";//必须手动添加事件处理器serialPort1.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);}//串口数据接收事件private void port_DataReceived(object sender, SerialDataReceivedEventArgs e){if (!radioButton3.Checked)//如果为字符模式接收{string str = serialPort1.ReadExisting();//字符串方式读textBox1.AppendText(str);}else//数值接收{//定义缓冲区，因为串口事件触发时不是实时的byte[] data = new byte[serialPort1.BytesToRead];serialPort1.Read(data, 0, data.Length);foreach(byte Member in data){string str = Convert.ToString(Member, 16).ToUpper();//空位补0textBox1.AppendText("0x" + (str.Length == 1 ? "0" + str : str) + " ");}}}private void button1_Click(object sender, EventArgs e){try{serialPort1.PortName = comboBox1.Text;serialPort1.BaudRate = Convert.ToInt32(comboBox2.Text);//十进制数据转换serialPort1.Open();button1.Enabled = false;//打开串口按钮不可用button2.Enabled = true;//关闭串口}catch{MessageBox.Show("端口错误，请检查串口", "错误");}}private void button2_Click(object sender, EventArgs e){try{serialPort1.Close();button1.Enabled = true;button2.Enabled = false;}catch(Exception err)//一般情况下关闭串口不会出错，所以不需要加处理程序{}}private void button3_Click(object sender, EventArgs e){byte[] Data = new byte[1];//判断串口是否打开if (serialPort1.IsOpen){if(textBox2.Text != ""){if (!radioButton1.Checked){try{serialPort1.WriteLine(textBox2.Text);}catch (Exception err){MessageBox.Show("串口数据写入错误", "错误");serialPort1.Close();button1.Enabled = true;button2.Enabled = false;}}else{//取余运算防止用户输入的字符为奇数个for(int i = 0; i < (textBox2.Text.Length - textBox2.Text.Length % 2) / 2; i++){Data[0] = Convert.ToByte(textBox2.Text.Substring(i * 2, 2), 16);serialPort1.Write(Data, 0, 1);}if(textBox2.Text.Length % 2 != 0){Data[0] = Convert.ToByte(textBox2.Text.Substring(textBox2.Text.Length - 1, 1), 16);serialPort1.Write(Data, 0, 1);}}}}}}
}