asp.Net 中获取一周第一天,一月第一天等实现代码

代码如下:

DateTime dt = DateTime.Now; 
//本月第一天时间 
DateTime dt_First = dt.AddDays(-(dt.Day) + 1); 
Label1.Text = dt_First.ToString("yyyy-MM-dd"); 
//将本月月数+1 
DateTime dt2 = dt.AddMonths(1); 
//本月最后一天时间 
DateTime dt_Last = dt2.AddDays(-(dt.Day)); 
Label2.Text = dt_Last.ToString("yyyy-MM-dd"); 
int weeknow = Convert.ToInt32(System.DateTime.Now.DayOfWeek); 
int daydiff = (-1) * weeknow + 1; 
int dayadd = 7 - weeknow; 
//本周第一天 
lblBegin.Text = System.DateTime.Now.AddDays(daydiff).ToString("yyyy-MM-dd"); 
//本周最后一天 
lblEnd.Text = System.DateTime.Now.AddDays(dayadd).ToString("yyyy-MM-dd");