什么是IEquatable，只是压倒一切的Object.Equals（）之间的区别是什么？ [英] What's the difference between IEquatable and just overriding Object.Equals()?
问题描述
我希望我的食品类能够测试时，它等于另一个类。稍后我会用它对付一个列表，我想使用它的List.Contains（）方法。我应该实现IEquatable或者只是覆盖的Object.Equals（）？从MSDN：
I want my Food class to be able to test whenever it is equal to another class. I will later use it against a List, and I want to use its List.Contains() method. Should I implement IEquatable or just override Object.Equals()? From MSDN:
该方法被确定平等 使用默认的相等比较， 由对象的定义 实施 IEquatable.Equals方法对于T （值的列表中的类型）。
This method determines equality by using the default equality comparer, as defined by the object's implementation of the IEquatable.Equals method for T (the type of values in the list).
因此，我的下一个问题是：在.NET框架的哪些功能/类使用的Object.Equals（）？我应该首先使用它？
So my next question is: which functions/classes of the .NET framework make use of Object.Equals()? Should I use it in the first place?
感谢
推荐答案
主要的原因是性能。当仿制药进行了介绍.NET 2.0中，他们可以添加一堆整齐的类，如名单，其中，T＆GT; ，词典＆LT; K，V＆GT; ，的HashSet＆LT; T＆GT; 等，这些结构经常使用 GetHash code 和等于。但对于值类型此要求的拳击。 IEquatable＆LT; T＆GT; 让结构实现一个强类型等于方法，所以没有拳击是必需的。因此，更好的性能使用值类型时泛型集合。
The main reason is performance. When generics were introduced in .NET 2.0 they were able to add a bunch of neat classes such as List<T>, Dictionary<K,V>, HashSet<T>, etc. These structures make heavy use of GetHashCode and Equals. But for value types this required boxing. IEquatable<T> lets a structure implement a strongly typed Equals method so no boxing is required. Thus much better performance when using value types with generic collections.
引用类型不受益很多，但在 IEquatable＆LT; T＆GT; 的实施确实让你避免从铸 System.Object的，可以有所作为，如果它经常被称为。
Reference types don't benefit as much but the IEquatable<T> implementation does let you avoid a cast from System.Object which can make a difference if it's called frequently.
正如在<一个href="http://blogs.msdn.com/jaredpar/archive/2009/01/15/if-you-implement-iequatable-t-you-still-must-override-object-s-equals-and-gethash$c$c.aspx">Jared帕森斯的博客不过，你仍然必须实现对象覆盖。
As noted on Jared Parson's blog though, you still must implement the Object overrides.
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