根据用户输入的年份和季度。获取该季度的开始和结束时间

    /// <summary>
    /// 根据年份和季度。获取该季度的开始和结束时间
    /// </summary>
    /// <param name="quarter">季度</param>
    /// <returns></returns>
    private void GetQurater(int year,string quarter)
    {
        DateTime dt = new DateTime();
        switch (quarter)
        {
            case "第一季度":
                dt = new DateTime(year, 1, 1);
                break;
            case "第二季度":
                dt = new DateTime(year, 4, 1);         
                break;
            case "第三季度":
                dt = new DateTime(year, 7, 1);           
                break;
            case "第四季度":
                dt = new DateTime(year, 10, 1);             
                break;

        }

        //本季度初
       string  start = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day).ToString("yyyy-MM-01");  //获取本季度的最后一天
       string  end = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day).AddMonths(3).AddDays(-1).ToString("yyyy-MM-dd"); 
    }

 

 

 

第二种

        /// <summary>
        /// 根据季度 获取开始时间和结束时间
        /// </summary>
        /// <param name="quarter">季度</param>
        /// <returns></returns>
        private Tuple<DateTime, DateTime> GetQurater(string quarter)
        {
            DateTime dt = new DateTime();
            switch (quarter)
            {
                case "一季度":
                    dt = DateTime.Parse($"{DateTime.Now.Year},1, 01");
                    break;
                case "二季度":
                    dt = DateTime.Parse($"{DateTime.Now.Year},4, 01");
                    break;
                case "三季度":
                    dt = DateTime.Parse($"{DateTime.Now.Year},7, 01");
                    break;
                case "四季度":
                    dt = DateTime.Parse($"{DateTime.Now.Year},10, 01");
                    break;
 
            }
 
            //本季度初
            string start = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day).ToString("yyyy-MM-01 00:00:00");  //本季度初
            //获取本季度的最后一天
            string end = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day).AddMonths(3).AddDays(-1).ToString("yyyy-MM-dd 23:59:59"); ;  //
 
            return Tuple.Create(DateTime.Parse(start), DateTime.Parse(end));
        }