摘要： usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;namespaceWyfClass{publicclasstools{//////得到本周第一天(以星期天为第一天)/////////publicDateTimeGetWeekFirstDaySun(DateTimedatetime){//星期天为第一天intweeknow=Convert.ToInt32(datetime.DayOfWeek);intdaydiff=(-1)*weeknow;//本周第一天stringFirstDay=da 阅读全文