WinForm(C#)倒计时（年月日时分秒）

时间：2010-11-22 来源：天行健自强不息

   public partial class FormTime : Form
    {
        public FormTime()
        {
            InitializeComponent();
        }

        private void FormTime_Load(object sender, EventArgs e)
        {
            timerMain.Enabled = true;
            timerMain.Interval = 1000;
            timerMain.Start();
        }

        private void timerMain_Tick(object sender, EventArgs e)
        {
            DateTime observeTime = DateTime.Parse("2023-11-22 22:45:30");//倒计时日期
            DateTime now = DateTime.Now;    //当前时间
            TimeSpan ts = observeTime.Subtract(now);    //两个时间之差
            StringBuilder result=new StringBuilder();   //存放结果
            int year=observeTime.Year - now.Year;       //得到相差的年
            int month = observeTime.Month - now.Month;  //得到相差的月
            int day = observeTime.Day - now.Day;        //得到相差的日

            int hmh=(observeTime.Hour-now.Hour)*3600+(observeTime.Minute-now.Minute)*60+(observeTime.Second-now.Second);

            //如果时分秒比现在的时间晚
            if(hmh<=0)
            {
                //向日借一
                day--;
                if((day<=0&&month>0)||(day<=0&&year>0))
                {
                    //如果天数小于0向月借一
                    day=GetDay(now.Year, now.Month)- now.Day + observeTime.Day;
                    month--;
                    if(month<0&&year>0)
                    {
                        //如果月数小于0，向年借一，同时把月专为正数
                        month += 12;
                        year--;
                    }
                }
            }

            //如果天数小于0向月借一
            if ((day < 0 && month > 0) || (day < 0 && year > 0))
            {
                day = GetDay(now.Year, now.Month) - now.Day + observeTime.Day;
                month--;
                if (month < 0 && year > 0)
                {
                    //如果月数小于0，向年借一，同时把月专为正数
                    month += 12;
                    year--;
                }
            }

            //如果月数小于0，向年借一，同时把月专为正数
            if (month < 0 && year > 0)
            {
                month += 12;
                year--;
            }

            if (year<0||(year == 0 && month < 0)||(year == 0 && month==0&&day<0))
            {
                lblShow.Text = "已超过日期";
                return;
            }

            if (year> 0)
            {
                result.Append(year+ "年");
            }
            if (month> 0)
            {
                result.Append(month+ "月");
            }
            if (day> 0)
            {
                result.Append(day+ "天");
            }
            if (ts.Hours > 0)
            {
                result.Append(ts.Hours + "时");
            }
            if (ts.Minutes > 0)
            {
                result.Append(ts.Minutes + "分");
            }
            if (ts.Seconds > 0)
            {
                result.Append(ts.Seconds + "秒");
            }
            if(result.Length==0)
            {
                result.Append("已超过日期");
            }
            lblShow.Text = result.ToString();
        }

        //输入月份后获得该月天数
        private int GetDay(int year, int month)
        {
            int result = 31;
            switch (month)
            {
                case 4:
                case 6:
                case 9:
                case 11:
                    result = 30;
                    break;
                case 2:
                    if ((year % 100 != 0) && (year% 4 == 0) || (year% 400 == 0))
                    {
                        result = 29;
                    }
                    else
                    {
                        result = 28;
                    }
                    break;
            }
            return result;
        }
    }

效果图：