C＃.Net從當前日期獲取上個月的最後一天

Question

請快速表達任何人嗎？

Answer 1

var now = DateTime.Now;  
var firstDayCurrentMonth = new DateTime(now.Year, now.Month, 1); 

var lastDayLastMonth = firstDayCurrentMonth.AddDays(-1); 

Answer 2

DateTime now = DateTime.Now; 
DateTime lastDayOfLastMonth = now.Date.AddDays(-now.Day); 

Answer 3

嘗試DateTime.DaysInMonth(int year, int month) method

下面是一個例子：

DateTime oneMonthAgo = DateTime.Now.AddMonths(-1); 
int days = DateTime.DaysInMonth(oneMonthAgo.Year, oneMonthAgo.Month);