T türü iki arabirimi bile uygulamazsa varsayılan alınlaştırıcı yoktur ve bir karşıtlaştırıcı veya önlaştırma temsilcisi açıkçaça sağlanmalıdır.
Hackathon yarışmalarına, uygulayım bilimi meydanında kariyer yapmayı hedefleyen ya da bu alanda deneyime mevla olan el âlem beklabilir.
The CompareTo method would be the default way of ordering your User class, perhaps comparing by Name. If you then decided that you wanted to sort a list of User objects by another property, say Age, you could write a class that implemented IComparer instead of altering CompareTo inside User. This would perform the custom sorting, for example:
CodeFuller's answer will work fine, but as an alternative option, you could use MoreLINQ and its DistinctBy method, which would avoid you needing to create a separate class at all:
Your GetHashCode implementation always returns the same value. Distinct relies on a good hash function to work efficiently because it internally builds a hash table.
The comparer will validate that prop1 is the same (and add B to the pool), then validate that prop2 is the same (and add C to the pool), and when it validates prop3, even though they're different, since both B and C are in the pool, the comparer will consider them C# IEqualityComparer nerelerde kullanılıyor to be the same.
Oluşturduğunuz sınıfı, koleksiyon oluştururken veya karşıtlaştırma müstelzim başka senaryolarda kullanabilirsiniz.
According to the IEqualityComparer code example provided by microsoft, you will want to use the new keyword (so hiding the C# IEqualityComparer Nasıl Kullanılır Equals implementation of the object) for implementing Equals.
So what happens when it comes time to actually C# IEqualityComparer Nasıl Kullanılır deduce the type argument? We have two candidates: Position and BaseClass. Both satisfy the stated bounds. Position satisfies the first bound because it is C# IEqualityComparer nerelerde kullanılıyor identical to the first bound, and satisfies the second bound because it is smaller than the second bound.
operating on different types of classes, even complex types including sub-objects or nested lists. And derece only on simple classes comprising only primitive type properties.
... the above suggests I should create a custom collection for any T implementing IEquatable. Would a collection like List have some kind of subtle bug in it otherwise?
In the LINQ world, generating the IEqualityComparer interface is a tedious task, especially because we don’t have sufficient time. Our generic class comes in handy for making things easier for us.
1 shouldn't this yapan if collections contains a null? however quick experiment on VS C# Interactive doesn't seem to throw null ref exception!
If things don't seem to be C# IEqualityComparer Kullanımı working (such bey duplicate key errors when doing ToDictionary) put a breakpoint inside Equals to make sure it's being hit and make sure you have GetHashCode defined (with override keyword).