blocks|key|2815575|text|来自the+documentation+of+DateTime.MinValue|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2815576|2815577|+MinValue定义分配给未初始化的DateTime变量的日期和时间。|blockquote|2815578|2815579|2815580|因此，结果日期将是相同的。因为DateTime是一个值类型，所以这两个选项应该是等价的。就我个人而言，我更喜欢编写DateTime.MinValue，因为它是自我记录的。|style|CODE|2815581|PS:如果您的数据可以包含(有意义的)空值，那么您可能需要考虑使用nullable+types+(DateTime?)。|2815582|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.datetime.minvalue.aspx|1|http://msdn.microsoft.com/en-us/library/1t3y8s4s.aspx^0|2|12|0|0|0|0|0|0|F|8|1L|H|0|1D|9|X|E|1|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|D|3|-4|5|6|7|13|8|@]|9|@]|C|$]]|$1|E|3|F|5|G|7|14|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|15|8|@]|9|@]|C|$]]|$1|I|3|-4|5|6|7|16|8|@]|9|@]|C|$]]|$1|J|3|K|5|6|7|17|8|@$A|18|B|19|L|M]|$A|1A|B|1B|L|M]]|9|@]|C|$]]|$1|N|3|O|5|6|7|1C|8|@$A|1D|B|1E|L|M]]|9|@$A|1F|B|1G|1|1H]]|C|$]]|$1|P|3|-4|5|6|7|1I|8|@]|9|@]|C|$]]]|Q|$R|$5|S|T|U|C|$V|W]]|X|$5|S|T|U|C|$V|Y]]]]

From <a href="http://msdn.microsoft.com/en-us/library/system.datetime.minvalue.aspx" rel="noreferrer">the documentation of DateTime.MinValue</a>:

<blockquote>
 MinValue defines the date and time that is assigned to an uninitialized DateTime variable.
</blockquote>

Thus, the resulting date will be the same. Since <code>DateTime</code> is a value type, both options should be equivalent. Personally, I prefer to write <code>DateTime.MinValue</code>, since it's self-documenting.

PS: You might want to consider using <a href="http://msdn.microsoft.com/en-us/library/1t3y8s4s.aspx" rel="noreferrer">nullable types</a> (<code>DateTime?</code>), if your data can contain (meaningful) null values.

blocks|key|971404|text|没有“适当”的方法。人们建立了一个约定，团队也遵循了这个约定。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|971405|如果负责的开发人员确定，DateTime.MinValue和新的DateTime+()是null的有效定义。|971406|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

There is no "proper" way. There is a convention that people set up and that the team follows.

DateTime.MinValue and new DateTime () are valid definitions for a null, if the developer in charge determines so.

blocks|key|2815651|text|我会说总是使用MinValue，因为这样您就可以确切地知道它的价值是什么。当您简单地使用新的DateTime()时，您是在初始化它以保存值，而不是指定要放入其中的值。显式地将一个值放入其中也会更简洁和清晰。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2815652|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I would say to always use MinValue because then you know exactly what value is in it. When you simply use new DateTime() you are initializing it to hold a value, but not specifying what value to place into it. It is also a lot cleaner and clearer to explicitly put a value into it.

blocks|key|1406754|text|DateTime+的默认值是DateTime+DateTime.MinValue，所以我猜您使用其中的哪一个并不重要;)|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|1406755|entityMap^0|9|5|N|H|0^^$0|@$1|2|3|4|5|6|7|I|8|@$9|J|A|K|B|C]|$9|L|A|M|B|D]]|E|@]|F|$]]|$1|G|3|-4|5|6|7|N|8|@]|E|@]|F|$]]]|H|$]]

Default value of DateTime is the <code>DateTime.MinValue</code>, so I guess it doesn't matter which of these you use ;)

blocks|key|971467|text|通常，我会显式处理NULL的情况。大致是这样的：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|971468|if+(!sqlQueryResults.IsNull("Data"))
++++DoComputationDependantOnDateTime((DateTime)+sqlQueryResults["Data"]);|code-block|syntax|javascript|971469|在某些情况下，即使不存在数据，执行逻辑也可能是有意义的。在这种情况下，只有您知道从哪个默认值开始。可能的候选人：|971470|971471|DateTime.MinValue|unordered-list-item|971472|DateTime.MaxValue|971473|DateTime.Now|971474|971475|我永远不会使用new+DateTime()，因为它的可读性很差。该语句返回什么？您(以及项目中的未来开发人员)可能需要查看文档以确定该值的初始化值是什么。|971476|entityMap^0|9|4|0|0|0|0|0|H|0|0|H|0|0|C|0|0|7|E|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|P|7|18|8|@$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|S|3|T|5|P|7|1B|8|@$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|U|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]|$1|V|3|W|5|6|7|1F|8|@$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|X|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]]|Y|$]]

Usually, I would handle the <code>NULL</code> case explicitly. Something along these lines:

<pre><code>if (!sqlQueryResults.IsNull("Data"))
 DoComputationDependantOnDateTime((DateTime) sqlQueryResults["Data"]);
</code></pre>

In some cases, it might make sense to perform the logic even if no data is present. In such cases, only you know what default value to start from. Likely candidates:

<ul>
<li><code>DateTime.MinValue</code></li>
<li><code>DateTime.MaxValue</code></li>
<li><code>DateTime.Now</code></li>
</ul>

I would never use <code>new DateTime()</code> as it has very poor readability. What does that statement return? You (and future developers on the project) might have to look into the documentation to figure out what the value is initialized to.

blocks|key|967937|text|表示空值最易维护的方式是使用Nullable<DateTime>，即DateTime?。这样，空值就被清楚地表示为非值，而不是需要特殊处理的魔术值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|967938|(当然，null值也需要特殊处理，但很难忽略它。)|967939|如果你使用一个神奇的值来表示空值，那么没有比其他值更好的值了。您可以使用DateTime.MinValue或new+DateTime()+(它们产生相同的结果)，也可以使用应用程序使用的范围之外的任意值。|967940|像DateTime.MinValue这样的值有一点优势，因为它已经被定义为常量，另一方面，您可以定义自己的常量，它的名称稍微更好一些，例如：|967941|public+const+DateTime+DateThatMeansNull+=+new+DateTime(1685,+3,+21);|code-block|syntax|javascript|967942|entityMap^0|E|I|Y|9|0|0|10|H|1I|E|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|13|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|14|8|@]|D|@]|E|$O|P]]|$1|Q|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|R|$]]

The most maintainable way of representing a null value would be to use a <code>Nullable&lt;DateTime&gt;</code> i.e. <code>DateTime?</code>. That way the null value is clearly represented as a non-value instead of a magic value that needs special treatment.

(The null value of course also needs special treatment, but it's much harder to overlook.)

If you use a magic value to represent null values, no value is much better than any other. You can use <code>DateTime.MinValue</code> or <code>new DateTime()</code> (which give the same result), or you can use any arbitrary value that is outside the range that your application is using.

A value like DateTime.MinValue has a slight advantage as it's already defined as a constant, on the other hand you can define your own constant that has a slightly better name, for example:

<pre><code>public const DateTime DateThatMeansNull = new DateTime(1685, 3, 21);
</code></pre>

When getting SQL DateTime Resharper suggests to use <code>new DateTime()</code> when value is <code>DBNull.Value</code>. I've always used <code>DateTime.MinValue</code>. Which is the proper way?

<pre><code>DateTime varData = sqlQueryResult["Data"] is DateTime ? (DateTime) sqlQueryResult["Data"] : new DateTime();
</code></pre>

DateTime.MinValue vs new DateTime() in C#

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在获取SQL时，Resharper建议在DateTime为DBNull.Value时使用new DateTime()。我一直使用DateTime.MinValue。哪种方式才是正确的？DateTime varData = sqlQueryResult["Data"] is DateTime ? (DateTime) s...

问DateTime.MinValue vs C#中的新DateTime()
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