C# 将 UTC DateTime 转换为 DateTimeOffset

Convert UTC DateTime to DateTimeOffset

提问by Fabian

I need to convert UTCdate strings to DateTimeOffsets.

我需要将UTC日期字符串转换为DateTimeOffsets.

This must work with a timezone which differs from the computers timezone.E.g. current computer timezone is +02:00, but I want to create a DateTimeOffset with offset -4:00.

这必须适用于与计算机时区不同的时区。例如，当前计算机时区是 +02:00，但我想创建一个偏移量为 -4:00 的 DateTimeOffset。

I already read lot of questions here on stackoverflow, but none of them solved my problem.

我已经在 stackoverflow 上阅读了很多问题，但没有一个能解决我的问题。

That is what I need to do:

这就是我需要做的：

Input:"2012-11-20T00:00:00Z"

输入：“2012-11-20T00:00:00Z”

Output:DateTimeOffset with:

输出：DateTimeOffset 与：

• UtcDateTime of 2012-11-20 00:00
• the correct Utc offset for the defined timezone (01:00 in this example)
• LocalDateTime: 2012-11-20 01:00(= UtcDateTime + Offset)

• UtcDateTime of 2012-11-20 00:00
• 定义时区的正确 Utc 偏移量（本例中为 01:00）
• LocalDateTime: 2012-11-20 01:00(= UtcDateTime + Offset)

Of course daylight saving must be taken into account.

当然，必须考虑夏令时。

edit: To make things even clearer, please try to complete the following code snippet:

编辑：为了使事情更清楚，请尝试完成以下代码片段：

DateTimeOffset result;
const string dateString = "2012-11-20T00:00:00Z";
var timezone = TimeZoneInfo.FindSystemTimeZoneById("W. Europe Standard Time"); //this timezone has an offset of +01:00:00 on this date

//do conversion here

Assert.AreEqual(result.Offset, new TimeSpan(1, 0, 0));  //the correct utc offset, in this case +01:00:00
Assert.AreEqual(result.UtcDateTime, new DateTime(2012, 11, 20, 0, 0, 0)); //equals the original date
Assert.AreEqual(result.LocalDateTime, new DateTime(2012, 11, 20, 1, 0, 0));

采纳答案by Matt Johnson-Pint

Here is the solution you are looking for:

这是您正在寻找的解决方案：

const string dateString = "2012-11-20T00:00:00Z";
var timezone = TimeZoneInfo.FindSystemTimeZoneById("W. Europe Standard Time"); //this timezone has an offset of +01:00:00 on this date

var utc = DateTimeOffset.Parse(dateString);
var result = TimeZoneInfo.ConvertTime(utc, timezone);

Assert.AreEqual(result.Offset, new TimeSpan(1, 0, 0));  //the correct utc offset, in this case +01:00:00
Assert.AreEqual(result.UtcDateTime, new DateTime(2012, 11, 20, 0, 0, 0)); //equals the original date
Assert.AreEqual(result.DateTime, new DateTime(2012, 11, 20, 1, 0, 0));

Note that you were incorrectly testing the .LocalDateTimeproperty - which is alwaysgoing to convert the result to the local timezone of the computer. You simply need the .DateTimeproperty instead.

请注意，您错误地测试了该.LocalDateTime属性 - 它总是会将结果转换为计算机的本地时区。您只需要该.DateTime属性即可。

回答by Johan Larsson

Is this what you want:

这是你想要的吗：

[Test]
public void ParseUtcDateTimeTest()
{
    DateTime dateTime = DateTime.Parse("2012-11-20T00:00:00Z");
    Assert.AreEqual(new DateTime(2012, 11, 20, 01, 00, 00), dateTime);
    DateTimeOffset dateTimeOffset = new DateTimeOffset(dateTime);
    Assert.AreEqual(new TimeSpan(0, 1, 0, 0), dateTimeOffset.Offset);
}

• Note that my asserts are valid in Sweden (CET)
• There are a couple of overloads on DateTime.Parse()

• 请注意，我的断言在瑞典（CET）有效
• 有几个重载 DateTime.Parse()

Is this useful for your conversion:

这对您的转换有用吗：

[Test]
public void ConvertTimeTest()
{
? ? DateTime dateTime = DateTime.Parse("2012-11-20T00:00:00Z");
? ? TimeZoneInfo cstZone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard     Time");
? ? DateTime convertedTime = TimeZoneInfo.ConvertTime(dateTime, cstZone);
? ? Assert.AreEqual(new DateTime(2012, 11, 19, 18, 00, 00), convertedTime);
? ? TimeSpan baseUtcOffset = cstZone.BaseUtcOffset;
? ? Assert.AreEqual(new TimeSpan(0, -6, 0, 0), baseUtcOffset);
}

回答by VRC

const String dateString = "2012-11-20T00:00:00Z"; 
var offsetDate = DateTimeOffset.Parse(dateString); 
var offsetDate2 = DateTime.Parse(dateString);

Output is

输出是

offsetDate  {20-11-2012 0:00:00 +00:00}    System.DateTimeOffset
offsetDate2 {20-11-2012 1:00:00}           System.DateTime