将DateTime设置为月初

Question

如何在C#中将DateTime设置为本月的第一天？

Answer 1

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

Answer 2

像这样的东西会起作用

DateTime firstDay = DateTime.Today.AddDays(1 - DateTime.Today.Day);

Answer 3

派对有点晚了,但这是一个扩展方法,为我做了诀窍

public static class DateTimeExtensions
{
  public static DateTime FirstDayOfMonth(this DateTime dt)
  {
    return new DateTime(dt.Year, dt.Month, 1);
  }
}

Answer 4

public static DateTime FirstDayOfMonth(this DateTime current)
{
    return current.AddDays(1 - current.Day);
}