什么是比较两个日期时间在C＃中的平等的最好方式......但只有在一定的精度？ [英] What's the best way to compare the equality of two DateTime's in C#... but only to a certain precision?

问题描述

我有两个日期时间，一名来自时间戳，另一个我在代码中产生。我需要测试他们的平等，并会喜欢做没有太多的表情。这里是我的两个日期的例子：

I have two datetimes, one from a timestamp, and another I'm generating in code. I need to test their equality, and would love to do it without too many expressions. Here's an example of my two dates:

DateTime expireTimeStampUTC = 
    DateTime.Parse(UTCValueFromDatabase));
DateTime expectedExpireTime = 
    DateTime.UtcNow.AddHours(NumberOfExpectedHoursInConfig);

这是一个测试过高精度：

This is too high precision of a test:

如果（expireTimeStampUTC.Equals（expectedExpireTime））{}

if (expireTimeStampUTC.Equals(expectedExpireTime)){}

我如果他们精确到秒，就在小时无所谓了。

I don't care if they're exact to the second, just the hour.

难道可能会做这样的事情化合物最好的解决办法：

Could it possibly be the best solution to do something compound like this:

if (expireTimeStampUTC.Date.Equals(expectedExpireTime.Date))
{
    if (!expireTimeStampUTC.Hour.Equals(expectedExpireTime.Hour))
    {
        pass = false;
    }
}

我不是最有经验与C＃.. 。有一些高贵的方式来做到这一点？

I'm not the most experienced with C#... is there some elegent way to do this?

推荐答案

如果您遇到的问题是，因为他们是一个数据库类型，你可以转换成该类型和比较那里，我们失去了约一毫秒转换为SQLDateTimes上大致DB的1/3节省/增益。

If the problem you are having is because of them is a database type, you could convert to that type and compare there, we lose/gain about a millisecond converting to SQLDateTimes on roughly 1/3 of DB saves.

如果没有，比较单元你真正关心的：

If not, compare the unit you actually care about:

DateTime dt1 = DateTime.UtcNow;
DateTime dt2 = DateTime.UtcNow.AddMinutes(59); // or 1 or 61 for test values;

// if the dates are in the same hour (12:10 == 12:50, 1:58 != 2:02)
if(dt1.Hour == dt2.Hour) // result

或者如果你关心自己是一个小时的时间跨度内

or if you care that they are within an hour time span

// if the dates are within one hour of each other (1:58 == 2:02, 3:30 != 4:45)
if((dt1 - dt2).Duration() < TimeSpan.FromHours(1)) // result

下面减去日期生成的时间跨度，持续时间的绝对值，然后我们从我们关心（FromHours）单位明确创建的限制和比较。

Here subtracting dates generates a time span, the duration is the 'absolute value' and then we create the limit explicitly from a unit we care about (FromHours) and compare.

最后一行是我能想到做一个特定的时间范围内平等干净。

The last line is as clean as I can think to do equality within a particular time span.

这篇关于什么是比较两个日期时间在C＃中的平等的最好方式......但只有在一定的精度？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！