C#、VB获取本月第一天、本月最后一天

C#获取本月第一天与最后一天：

//本月第一天
todayMonthFirstDay = new DateTime(today.Year, today.Month, 1);
//本月最后一天
todayMonthLastDay = todayMonthFirstDay.AddMonths(1).AddDays(-1);
txtDateStart.Text = todayMonthFirstDay.ToLongDateString();
txtDateEnd.Text = todayMonthLastDay.ToLongDateString();

VB获取本月第一天与最后一天：

'本月第一天
todayMonthFirstDay = CDate(Year(today) & "-" & Month(today))
'本月最后一天
todayMonthLastDay = CDate(Year(today) & "-" & Month(today) + 1).AddDays(-1)