//日期开始时间 yyyy-MM-dd 00:00:00
DateTime dStart = this.DTPstartTime.Value.Date;
this.DTPstartTime.Value = dStart;
//日期结束时间 yyyy-MM-dd 23:59:59
DateTime dEnd = new DateTime(this.DTPendTime.Value.Year,this.DTPendTime.Value.Month, this.DTPendTime.Value.Day, 23, 59, 59);
this.DTPendTime.Value = dEnd;