要将引用类型的值用作字典键，必须做什么？
假设我有一个类 T，我想将其用作 Dictionary 集合中的键。
我必须在 T 中实现什么，以便这些键基于 T 的值而不是 T 引用？
我希望它只是 GetHashCode()。
Suppose I have a class T that I want to use as a key in a Dictionary<T,U> collection.
What must I implement in T so that these keys are based on values of T rather than T references?
I'm hoping it's just GetHashCode().
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（4）
您必须实现 GetHashCode() 和 Equals()。
字典是底层的哈希表，因此您可能需要阅读以下内容： Equals/GetHashCode 的陷阱 – 哈希表如何工作？
You must implement GetHashCode() and Equals().
Dictionary is a Hashtable below the covers, so you might want to read this: Pitfalls Of Equals/GetHashCode – How Does A Hash Table Work?
如果您不在字典构造函数中传递任何
IEqualityComparer，它将使用EqualityComparer.Default ，MSDN 定义为：因此，实现
IEquatable将是我的选择（如果实现它，覆盖Equals和也是有意义的无论如何，>GetHashCode）。If you don't pass any
IEqualityComparer<T>in the dictionary constructor, it will useEqualityComparer<T>.Defaultwhich is defined by MSDN as :So implementing
IEquatable<T>would be my choice (if you implement it it also makes sense to overrideEqualsandGetHashCodeanyway).要么实现
Equals和GetHashCode或者创建适当的IEqualityComparer具有适合您的地图的正确形式的相等匹配。我更喜欢是有意义的……如果可以的话。 （
IEqualityComparer路线：在许多情况下，没有一种明显正确的平等形式 - 您希望根据情况以不同的方式将对象视为平等。在这种情况下，自定义相等比较器正是您所需要的。当然，如果存在自然的相等操作，那么在类型本身中实现 IEquatableIEqualityComparer的另一个好处是您可以为您无法控制的类型实现它。）Either implement
EqualsandGetHashCodeor create an appropriateIEqualityComparer<T>which has the right form of equality matching for your map.I rather like the
IEqualityComparer<T>route: in many cases there isn't one obviously-right form of equality - you want to treat objects as equal in different ways depending on the situation. In that case, a custom equality comparer is just what you need. Of course, if there is a natural equality operation, it makes sense to implementIEquatable<T>in the type itself... if you can. (Another benefit ofIEqualityComparer<T>is that you can implement it for types you have no control over.)您需要覆盖
Equals(object obj)。当您修改Equals时，始终期望您实现GetHashCode。请阅读 MSDN 上的这篇文章。You need to override
Equals(object obj). It is always expected that you implementGetHashCodewhen you modifyEquals. Read this article at MSDN.