.net - 如何在没有日期组件的情况下获取 UTC 时间？

Question

如何获得UTC time没有任何日期的组件？

当我尝试分配Date.UtcNow给Date变量时，出现以下异常：

时间值包含不允许的日期组件

我正在分配Date.UtcNow给Date第三方 DLL 中的属性。我不知道这是否是不同版本的 .NET 的问题，或者是否是 DLL 是用 C# 编写的并且我在 VB.NET 中使用它。我可以绕过它的唯一方法是使用Date.UtcNow.ToString.

Answer 1

如果您只想要时间部分，则需要获取TimeOfDay属性。这是一个TimeStamp：

Dim currentTime As TimeSpan = DateTime.UtcNow.TimeOfDay

Answer 2

The error message you provided:

Time value contains a date component which is not permitted

Is not a standard message from any exception in the .Net framework. You said (in comments) that you are are using a third-party dll. The exception is likely raised in that dll.

Without knowing more details about this dll, there's not a whole lot of advice I can offer. I can make some assumptions though. You said you are doing something like this:

thirdPartyObject.Date = DateTime.UtcNow.ToString

If this is even compiling then the Date property on the object is not of type DateTime. It is either a string or an object.

You also said you tried:

thirdPartyObject.Date = DateTime.UtcNow

If this compiles and throws the exception you mentioned, then it cannot be a string. So I conclude that it must be of type object.

This is quite bizarre. The third party object has a property of type object called Date that only wants a time? Whomever designed this API must not have been thinking about usability!

As a super-wild-ass-guess, I would try something like this:

thirdPartyObject.Date = DateTime.MinValue + DateTime.UtcNow.TimeOfDay

Or maybe it does want a string, then try:

thirdPartyObject.Date = DateTime.UtcNow.ToString("HH:mm:ss")

If you can clarify what third-party object you are using, or what it's API looks like for the Date property, then perhaps I can refine my answer.

Answer 3

Dim dt As Date = Now.ToUniversalTime.ToShortTimeString