我怎样才能获得一个月的最后一天？

Question

如何在C#中找到该月的最后一天？

例如,如果我的日期是03/08/1980,那么如何获得第8个月的最后一天(在这种情况下为31)？

Answer 1

这个月的最后一天,你得到这样的,返回31:

DateTime.DaysInMonth(1980, 08);

Answer 2

var lastDayOfMonth = DateTime.DaysInMonth(date.Year, date.Month);

Answer 3

DateTime firstOfNextMonth = new DateTime(date.Year, date.Month, 1).AddMonths(1);
DateTime lastOfThisMonth = firstOfNextMonth.AddDays(-1);

Answer 4

如果你想要一个月和一年的日期,这似乎是正确的:

public static DateTime GetLastDayOfMonth(this DateTime dateTime)
{
    return new DateTime(dateTime.Year, dateTime.Month, DateTime.DaysInMonth(dateTime.Year, dateTime.Month));
}

Answer 5

从下个月的第一天开始减去一天:

DateTime lastDay = new DateTime(MyDate.Year,MyDate.Month+1,1).AddDays(-1);

此外,如果您需要它也适用于12月:

DateTime lastDay = new DateTime(MyDate.Year,MyDate.Month,1).AddMonths(1).AddDays(-1);

Answer 6

您可以按如下方式扩展 DateTime；

public static class DateTimeMethods
{
    public static DateTime StartOfMonth(this DateTime date)
    {
        return new DateTime(date.Year, date.Month, 1, 0, 0, 0);
    }

    public static DateTime EndOfMonth(this DateTime date)
    {
        return date.StartOfMonth().AddMonths(1).AddSeconds(-1);
    }
}

并按如下方式使用它；

DateTime today = DateTime.Now;

DateTime startOfMonth = today.StartOfMonth();
DateTime endOfMonth = today.EndOfMonth();

Answer 7

您可以通过以下代码找到任何月份的最后日期:

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

Answer 8

您可以通过一行代码找到该月的最后一天:

int maxdt = (new DateTime(dtfrom.Year, dtfrom.Month, 1).AddMonths(1).AddDays(-1)).Day;

Answer 9

从 DateTimePicker:

第一次约会：

DateTime first_date = new DateTime(DateTimePicker.Value.Year, DateTimePicker.Value.Month, 1);

最后日期：

DateTime last_date = new DateTime(DateTimePicker.Value.Year, DateTimePicker.Value.Month, DateTime.DaysInMonth(DateTimePicker.Value.Year, DateTimePicker.Value.Month));

Answer 10

// Use any date you want, for the purpose of this example we use 1980-08-03.
var myDate = new DateTime(1980,8,3);
var lastDayOfMonth = new DateTime(myDate.Year, myDate.Month, DateTime.DaysInMonth(myDate.Year, myDate.Month));