How do i make sure that List<T>.Contains(T) works with my custom class?

问题

I use .net 2.0 (C#)

I have a Person class, and i pupulate List< Person> p from the database.

i know for a fact that my list has duplicates, but when i try to remove the duplicates they don't get removed.

Does my Person class need to implement any interfaces for List< T>.Contains(T) to work properly?

Any other ideas?

Thank you.

回答1:

Your Person class should implement IEquatable

回答2:

You should override Equals and GetHashCode method.

回答3:

The example you reference is not a solution for removing dupes from a list, it is a function that takes a list and yields an iterator that will exclude duplicates. If you need to dedupe the entire list in one go you would need to take the IEnumerable<T> returned from the function and pass it into a new List<T>.

回答4:

You need to overload Object.Equals(Object obj) in your class.

回答5:

The docs say "This method determines equality using the default equality comparer EqualityComparer(T).Default".

来源：https://stackoverflow.com/questions/593171/how-do-i-make-sure-that-listt-containst-works-with-my-custom-class