//计算天数     protected int getDays(DateTime date1, DateTime date2)     {         int days = 0;         if (date1.Year == date2.Year)         {             if (date1.Month < date2.Month)             {                 days = (date2.Day - date1.Day) + (date2.Month - date1.Month) * 30;             }             if (date2.Month == date1.Month)             {                 days = date2.Day - date1.Day;             }         }         else         {             DateTime date3 = Convert.ToDateTime(date1.Year + "- 12 - 31");             DateTime date4 = Convert.ToDateTime(date2.Year + "- 01 - 01");             int day1 = 0;             if (date1.Month < date3.Month)             {                 day1 = (date3.Day - date1.Day) + (date3.Month - date1.Month) * 30;             }             if (date3.Month == date1.Month)             {                 day1 = date3.Day - date1.Day;             }               int day2 = 0;             if (date4.Month < date2.Month)             {                 day2 = (date2.Day - date4.Day) + (date2.Month - date4.Month) * 30;             }             if (date4.Month == date2.Month)             {                 day2 = date2.Day - date4.Day;             }             days = day1 + day2;         }         return days;     }