DateTimeOffset错误:本地dateTime的UTC偏移量与偏移量参数不匹配

Question

我正在尝试创建一个将时间从一个时区转换为另一个时区的小方法.我认为这很简单,但是当我部署它时,我得到了这个错误The UTC Offset of the local dateTime parameter does not match the offset argument.我的猜测是因为服务器与用户不在同一时区,因为这将在世界各地使用.

public object ConvertDate(DateTime inputTime, string fromOffset, string toZone)
{
    var fromTimeOffset = new TimeSpan(0, - int.Parse(fromOffset), 0);
    var to = TimeZoneInfo.FindSystemTimeZoneById(toZone);
    var offset = new DateTimeOffset(inputTime, fromTimeOffset);
    var destination = TimeZoneInfo.ConvertTime(offset, to); 
    return destination.DateTime;
}

数字在哪里fromOffset,从用户时区转换为时间跨度,toZone是我们要转换为的区域的名称.此行发生错误var offset = new DateTimeOffset(inputTime, fromTimeOffset);

关于如何使这个工作的任何想法？

Answer 1

请参阅文档以了解抛出异常的原因:

ArgumentException:dateTime.Kindequals Local并且offset不等于系统本地时区的偏移量.

DateTime您收到的参数的Kind属性设置为Local.解决这个问题最简单的方法是设置Kind为Undefined.

public object ConvertDate(DateTime inputTime, string fromOffset, string toZone)
{
    // Ensure that the given date and time is not a specific kind.
    inputTime = DateTime.SpecifyKind(inputTime, DateTimeKind.Unspecified);

    var fromTimeOffset = new TimeSpan(0, - int.Parse(fromOffset), 0);
    var to = TimeZoneInfo.FindSystemTimeZoneById(toZone);
    var offset = new DateTimeOffset(inputTime, fromTimeOffset);
    var destination = TimeZoneInfo.ConvertTime(offset, to); 
    return destination.DateTime;
}

Answer 2

这是我用来解决这个令人难以置信的令人沮丧的框架决定的扩展方法。请参阅注释，处理此问题的最佳和最高效的方法是使用 的 ticks 构造函数DateTimeOffset，而不必分配另一个中间体DateTime来更改它的Kind属性。

    /// <summary>
    /// Converts a DateTime to a DateTimeOffset, without risking any onerous exceptions
    /// the framework quite unfortunately throws within the DateTimeOffset constructor, 
    /// such as they do when the source DateTime's Kind is not set to UTC. The best and 
    /// most performant way around this, which we do herein, is to simply construct the 
    /// new DateTimeOffset with the overload that excepts Ticks. Also, we will simply 
    /// return <see cref="DateTimeOffset.MinValue"/> if the source DateTime was 
    /// <see cref="DateTime.MinValue"/>.
    /// </summary>
    /// <param name="dt">Source DateTime.</param>
    /// <param name="offset">Offset</param>
    public static DateTimeOffset ToDateTimeOffset(this DateTime dt, TimeSpan offset)
    {
        // adding negative offset to a min-datetime will throw, this is a 
        // sufficient catch. Note however that a DateTime of just a few hours can still throw
        if (dt == DateTime.MinValue)
            return DateTimeOffset.MinValue;

        return new DateTimeOffset(dt.Ticks, offset);
    }

    public static DateTimeOffset ToDateTimeOffset(this DateTime dt, double offsetInHours = 0)
        => ToDateTimeOffset(dt, offsetInHours == 0 ? TimeSpan.Zero : TimeSpan.FromHours(offsetInHours));