By default, the two important methods are GetHashCode()
and Equals()
. It is important that if two things are equal (Equals()
returns true), that they have the same hash-code. For example, you might “return FooID;” as the GetHashCode()
if you want that as the match. You can also implement IEquatable<Foo>
, but that is optional:
class Foo : IEquatable<Foo> {
public string Name { get; set;}
public int FooID {get; set;}
public override int GetHashCode() {
return FooID;
}
public override bool Equals(object obj) {
return Equals(obj as Foo);
}
public bool Equals(Foo obj) {
return obj != null && obj.FooID == this.FooID;
}
}
Finally, another alternative is to provide an IEqualityComparer<T>
to do the same.