C#实现倒计时

- 日理万妓 2022-05-09 08:33 803阅读 0赞

# 一、效果 #

![006QSYQxly1fvwjf0cxcsj307m05cjrf.jpg][]

![006QSYQxly1fvwjjtcld2j307m05cwen.jpg][]

# 二、实现代码 #

DateTime dtNow, dtSet;//定义两个DateTime类型的变量，分别用来记录当前时间和设置的到期时间
    private void Form1_Load(object sender, EventArgs e)
    {
        timer1.Interval = 1000;//设置timer1计时器的执行时间间隔
        timer1.Enabled = true;//启动timer1计时器
        numericUpDown1.Value = DateTime.Now.Hour;//显示当前时
        numericUpDown2.Value = DateTime.Now.Minute;//显示当前分
        numericUpDown3.Value = DateTime.Now.Second;//显示当前秒
    }
    
    private void button1_Click(object sender, EventArgs e)
    {
        if (button1.Text == "设置")//判断按钮的文本是否为设置
        {
            button1.Text = "停止";//设置按钮的文本为停止
            timer2.Start();//启动timer2计时器
        }
        else if (button1.Text == "停止")//判断按钮的文本是否为停止
        {
            button1.Text = "设置";//设置按钮的文本为设置
            timer2.Stop();//停止timer2计时器
            label3.Text = "倒计时已取消";
        }
    }
    
    private void timer1_Tick(object sender, EventArgs e)
    {
        label7.Text = DateTime.Now.ToLongTimeString();//显示系统时间
        dtNow = Convert.ToDateTime(label7.Text);//记录系统时间
    }
    
    private void numericUpDown2_ValueChanged(object sender, EventArgs e)
    {
    
    }
    
    private void groupBox1_Enter(object sender, EventArgs e)
    {
    
    }
    
    private void timer2_Tick(object sender, EventArgs e)
    {
        //记录设置的到期时间
        dtSet = Convert.ToDateTime(numericUpDown1.Value + ":" + numericUpDown2.Value + ":" + numericUpDown3.Value);
        //计算倒计时
        long countdown = DateAndTime.DateDiff(DateInterval.Second, dtNow, dtSet, FirstDayOfWeek.Monday, FirstWeekOfYear.FirstFourDays);
        if (countdown > 0)//判断倒计时时间是否大于0
            label3.Text = "倒计时已设置，剩余" + countdown + "秒";//显示倒计时
        else
            label3.Text = "倒计时已到";
    }

[006QSYQxly1fvwjf0cxcsj307m05cjrf.jpg]: https://ws1.sinaimg.cn/large/006QSYQxly1fvwjf0cxcsj307m05cjrf.jpg
[006QSYQxly1fvwjjtcld2j307m05cwen.jpg]: https://ws1.sinaimg.cn/large/006QSYQxly1fvwjjtcld2j307m05cwen.jpg