using System;
using System.Windows.Forms;namespace WindowsForms
{public partial class Form1 : Form{public Form1(){InitializeComponent();}private void Form1_Load(object sender, EventArgs e){button1.Text = "开始计时";label1.Text = "时长";label2.Text = "剩余时间";timer1.Interval = 1000;for(int i = 1;i < 100;i++)  // 时长计数范围1-99秒{comboBox1.Items.Add($"{i} 秒");}comboBox1.SelectedIndex = 0;}// 开始计时按钮事件// 用户选择和初始化计时的逻辑放在 button1_Click 事件处理器里// 只需在按下按钮的时候才去获取一下comboBox1的值，而timer1_Tick每隔1秒就执行一次，没必要每隔1秒就获取一次comboBox1private void button1_Click(object sender, EventArgs e){string str = comboBox1.Text;string data = str.Substring(0, 2);time = Convert.ToInt16(data);  // 提取出前两位字符并转换为Int  将结果赋值给timeprogressBar1.Maximum = time;//设置进度条最大数值count = 0;timer1.Start();//开始计时}// 文本 时长private void label1_Click(object sender, EventArgs e){}// 文本 剩余时间private void label2_Click(object sender, EventArgs e){}// 剩余时间（秒）private void label3_Click(object sender, EventArgs e){}// (时长)下拉框事件private void comboBox1_SelectedIndexChanged(object sender, EventArgs e){label3.Text = comboBox1.SelectedItem.ToString();}// 进度条private void progressBar1_Click(object sender, EventArgs e){}int count;int time;// 定时器事件  只处理计时逻辑  每隔1000毫秒会被调用。private void timer1_Tick(object sender, EventArgs e){count++; //记录当前秒label3.Text = (time - count).ToString() + " 秒";   progressBar1.Value = count;if(count == time){timer1.Stop(); //关闭计时System.Media.SystemSounds.Asterisk.Play();//播放提示音MessageBox.Show("时间到了！", "提示");}}}
}