如何使用不同的格式格式化DateTime？ [英] How do I format a DateTime in a different format?

问题描述

我有一个字符串表示某种格式的日期，我希望格式不同。有人告诉我要使用 DateTime（尝试）ParseExact ，所以我做了：

I have a string representing a date in a certain format, that I wish to format differently. Someone told me to use DateTime.(Try)ParseExact, so I did:

var dateString = "2016-02-26";
var formatString = "dd/MM/yyyy";

var parsedDate = DateTime.ParseExact(dateString, formatString, null);

你看，我想格式化日期为 dd / MM / yyyy ，所以 26/02/2016 。但是，此代码抛出一个FormatException：

You see, I want to format the date as dd/MM/yyyy, so 26/02/2016. However, this code throws a FormatException:

字符串未被识别为有效的DateTime。

String was not recognized as a valid DateTime.

如何以不同的方式格式化DateTime？

How can I format a DateTime differently?

推荐答案

首先，DateTimes没有格式DateTime保持一段时间，一个标志表示该时刻是本地的，UTC还是未知的，就是这样。

First of all, DateTimes have no format. A DateTime holds a moment in time and a flag indicating whether that moment is local, UTC or unknown, and that's it.

DateTime格式化的唯一时刻是您将其值作为字符串输出。

The only moment a DateTime gets formatted, is when you output its value as a string.

您提供给的格式字符串（Try）ParseExact 是日期（时间）要解析的字符串在中。请参阅 MSDN：自定义日期和时间格式字符串以了解如何编写自己的格式字符串。

The format string you provide to (Try)ParseExact is the format that the date(time) string to parse is in. See MSDN: Custom Date and Time Format Strings to learn how you can write your own format string.

所以你要解析该字符串的代码是这样的，再次确保格式字符串匹配输入日期字符串的格式：

So the code you're looking for to parse that string is this, and again, make sure the format string matches the format of the input date string exactly:

var dateString = "2016-02-26";
var formatString = "yyyy-MM-dd";

var parsedDate = DateTime.ParseExact(dateString, formatString, null);

现在 parsedDate 持有一个DateTime值，可以输出您想要的格式（并注意，您必须转义 / ，因为它将被解释为当前文化的日期分隔符如上述MSDN链接中所述）：

Now parsedDate holds a DateTime value that you can output in your desired format (and note that you'll have to escape the /, as it'll be interpreted as "the date separator character for the current culture", as explained in above MSDN link):

var formattedDate = parsedDate.ToString("dd\\/MM\\/yyyy");

这将格式化所需格式的日期：

This will format the date in the desired format:

26/02/2016

这篇关于如何使用不同的格式格式化DateTime？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！