舍入日期时间对象 [英] Rounding DateTime objects

问题描述

我想将日期/时间四舍五入到图表应用程序的最近间隔.我想要一个如下所示的扩展方法签名，以便可以实现任何精度级别的舍入:

I want to round dates/times to the nearest interval for a charting application. I'd like an extension method signature like follows so that the rounding can be acheived for any level of accuracy:

static DateTime Round(this DateTime date, TimeSpan span);

这个想法是，如果我在十分钟的时间跨度内传递，它将四舍五入到最接近的十分钟间隔.我无法理解这个实现，希望你们中的一个人以前写过或使用过类似的东西.

The idea is that if I pass in a timespan of ten minutes, it will round to the nearest ten minute interval. I can't get my head around the implementation and am hoping one of you will have written or used something similar before.

我认为地板、天花板或最近的实施都可以.

I think either a floor, ceiling or nearest implementation is fine.

有什么想法吗?

感谢@tvanfosson &@ShuggyCoUk，实现如下:

Thanks to @tvanfosson & @ShuggyCoUk, the implementation looks like this:

public static class DateExtensions {
    public static DateTime Round(this DateTime date, TimeSpan span) {
        long ticks = (date.Ticks + (span.Ticks / 2) + 1)/ span.Ticks;
        return new DateTime(ticks * span.Ticks);
    }
    public static DateTime Floor(this DateTime date, TimeSpan span) {
        long ticks = (date.Ticks / span.Ticks);
        return new DateTime(ticks * span.Ticks);
    }
    public static DateTime Ceil(this DateTime date, TimeSpan span) {
        long ticks = (date.Ticks + span.Ticks - 1) / span.Ticks;
        return new DateTime(ticks * span.Ticks);
    }
}

并且是这样调用的:

DateTime nearestHour = DateTime.Now.Round(new TimeSpan(1,0,0));
DateTime minuteCeiling = DateTime.Now.Ceil(new TimeSpan(0,1,0));
DateTime weekFloor = DateTime.Now.Floor(new TimeSpan(7,0,0,0));
...

干杯！

推荐答案

Floor

long ticks = date.Ticks / span.Ticks;

return new DateTime( ticks * span.Ticks, date.Kind );

圆形(中点)

long ticks = (date.Ticks + (span.Ticks / 2) + 1)/ span.Ticks;

return new DateTime( ticks * span.Ticks, date.Kind );

天花板

long ticks = (date.Ticks + span.Ticks - 1)/ span.Ticks;

return new DateTime( ticks * span.Ticks, date.Kind );

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