倒计时

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;namespace 倒计时
{public partial class Form1 : Form{public Form1(){InitializeComponent();timer1.Interval = 800;}int a = 10;private void button1_Click(object sender, EventArgs e){if (timer1.Enabled){timer1.Stop();button1.Text = "开始";}else{timer1.Start();button1.Text = "暂停";}}private void timer1_Tick(object sender, EventArgs e){a--;if (a < 4){label2.ForeColor = Color.Red;}else{label2.ForeColor = Color.Green;}if (a < 0){timer1.Stop();button1.Text = "开始";}else{label2.Text = a.ToString();}}private void button2_Click(object sender, EventArgs e){a = 10;label2.Text = a.ToString();}}
}