DatePicker(日期选择自定义服务器控件)的实现[5]

                   int _year = int32.parse(dropyear.selecteditem.value);

                   int _month = int32.parse(dropmonth.selecteditem.value);

                   int _day = int32.parse(dropday.selecteditem.value);

                   if (_day > datetime.daysinmonth(_year, _month) )

                       throw new argumentexception("invalid date!");

                   return new datetime

                       (