Question

假设我有以下日期，时间和时区：2016-10-15, 1:00:00, America/Toronto。

如何创建表示指定区域中确切日期和时间的ZonedDateTime？

基本上我需要一个ZonedDateTime对象来表示确切时区的确切日期和时间。

如果跳过时间，我想在新时间添加小时刻度。例如：

如果00:00被跳到1:00，我试图在区域中获得00:30的时间，我希望结果是1:30，而不仅仅是1:00，这是第一次间隔。

如果00:00被跳到1:45，我试图在区域中获得时间00:20，我希望结果是2:05。

如果时间不明确，我。例如，发生两次，我想要伯爵的映射。

Answer 1

您所描述的正是Noda Time 2.0中LocalDateTime.InZoneLeniently的行为。（感谢Matt Johnson's change :)但是，由于它仍处于alpha状态，因此这是1.3.2的解决方案。基本上，您只需要一个适当的ZoneLocalMappingResolver，您可以使用Resolvers构建它。这是一个完整的例子。

using NodaTime.TimeZones;
using NodaTime.Text;

class Program
{
    static void Main(string[] args)
    {
        // Paris went forward from UTC+1 to UTC+2
        // at 2am local time on March 29th 2015, and back
        // from UTC+2 to UTC+1 at 3am local time on October 25th 2015.
        var zone = DateTimeZoneProviders.Tzdb["Europe/Paris"];

        ResolveLocal(new LocalDateTime(2015, 3, 29, 2, 30, 0), zone);
        ResolveLocal(new LocalDateTime(2015, 6, 19, 2, 30, 0), zone);
        ResolveLocal(new LocalDateTime(2015, 10, 25, 2, 30, 0), zone);
    }

    static void ResolveLocal(LocalDateTime input, DateTimeZone zone)
    {
        // This can be cached in a static field; it's thread-safe.
        var resolver = Resolvers.CreateMappingResolver(
            Resolvers.ReturnEarlier, ShiftForward);

        var result = input.InZone(zone, resolver);
        Console.WriteLine("{0} => {1}", input, result);
    }

    static ZonedDateTime ShiftForward(
        LocalDateTime local,
        DateTimeZone zone,
        ZoneInterval intervalBefore,
        ZoneInterval intervalAfter)
    {
        var instant = new OffsetDateTime(local, intervalBefore.WallOffset)
            .WithOffset(intervalAfter.WallOffset)
            .ToInstant();
        return new ZonedDateTime(instant, zone);
    }            
}

输出：

29/03/2015 02:30:00 => 2015-03-29T03:30:00 Europe/Paris (+02)
19/06/2015 02:30:00 => 2015-06-19T02:30:00 Europe/Paris (+02)
25/10/2015 02:30:00 => 2015-10-25T02:30:00 Europe/Paris (+02)

Answer 2

修改
以前的解决方案存在问题，例如DST期间的无效日期时间等等。

这是解决所有问题的新解决方案，并附有说明。感谢@Veeram。

// Transform the "time" in a localized time. var tzLocalTime = LocalDateTime.FromDateTime(time); try { // To get the exact same time in the specified zone. zoned = tzLocalTime.InZoneStrictly(zone); } catch(SkippedTimeException) { // This happens if the time is skipped // because of daylight saving time. // // Example: // If DST starts at Oct 16 00:00:00, // then the clock is advanced by 1 hour // which means Oct 16 00:00:00 is *skipped* // to Oct 16 01:00:00. // In this case, it is not possible to convert // to exact same date, and SkippedTImeException // is thrown. // InZoneLeniently will convert the time // to the start of the zone interval after // the skipped date. // For the example above, this would return Oct 16 01:00:00. // If someone schedules an appointment at a time that // will not occur, than it is ok to adjust it to what // will really happen in the real world. var originalTime = ste.LocalDateTime; // Correct for the minutes, seconds, and milliseconds. // This is needed because if someone schedueld an appointment // as 00:30:00 when 00:00:00 is skipped, we expect the minute information // to be as expected: 01:30:00, instead of 01:00:00. var minuteSecondMillisecond = Duration.FromMinutes(originalTime.Minute) + Duration.FromSeconds(originalTime.Second) + Duration.FromMilliseconds(originalTime.Millisecond); zoned = zLocalTime.InZoneLeniently(zone).Plus(minuteSecondMillisecond); } catch(AmbiguousTimeException ate) { // This happens when the time is ambiguous. // During daylight saving time, for example, // an hour might happen twice. // // Example: // If DST ends on Feb 19 00:00:00, then // Feb 18 23:00:00 will happen twice: // once during DST, and once when DST ends // and the clock is set back. // In such case, we assume the earlier mapping. // We could work with the second time that time // occur with ate.LaterMapping. zoned = ate.EarlierMapping; }

Noda Time - 从DateTime和TimeZoneId创建ZonedDateTime

2 个答案: