The Ultimate Guide To C# IEqualityComparer nerelerde kullanılıyor

The Ultimate Guide To C# IEqualityComparer nerelerde kullanılıyor

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I think the pool logic might be broken; you're adding objects which you see to the pool, and if the objects are on the pool then they're considered the same. It will özne if you have two objects of type A with three properties as shown below:

The sıkıntı is (and this is why I chose the IList in the first place) that at compile time I don't know the value of T. $endgroup$

Alternatively, you emanet write an empty comparer class that implements IEqualityComparer, and then pick the corresponding quick-fix from the Zir+Enter menu:

演算子（==）と（!=）のオーバーロードを実装します（推奨・必須ではない）

Internal: Denetleme, ancak aynı derlemedeki sınıflar tarafından erişilebilir hale gelir. Bu durumda, muayeneün erişimi belirlenmişdır ve ancak aynı derlemedeki özge sınıflar tarafından erişilebilir.

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It is essentially the same for this purpose with one subtle difference. In your first example you override Equals using a parameter of type Object and then have to cast it to Customer, however, in your second example you are able to have the parameter of type Customer which means there is no need to cast.

If you look C# IEqualityComparer nedir at the definition of Distinct there is only one generic type parameter involved (and hamiş one TCollection used for input and output collections and one TComparison for the comparer).

EDIT2: As mentioned in the comments doing reflection within Equals or even GetHashCode is a bad idea birli it´s usually quite slow and sevimli often be avoided. If you know the properties to be checked for eqality at compile-time you should definitly C# IEqualityComparer Kullanımı include them within those two methods birli doing so gives you much more safety.

If it is possible, güç we add an attribute to a property to say C# IEqualityComparer Kullanımı that this property is not relevant in the comparison?

When we make the inference from the comparer we say "IEqualityComparer is contravariant in T, so we hayat accept C# IEqualityComparer nedir BaseClass or any smaller type

One feature I wish C# IEqualityComparer Kullanımı .NET had which would improve the usefulness of such dictionaries would be a means of requesting the actual key object associated with a given key (so if the dictionary contained the string "WowZo" birli a key, one could look up "wowzo" and get "WowZo"; unfortunately, the only way to retrieve an actual key object, if TValue doesn't contain a redundant reference to it, is to enumerate the entire collection).

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Doing that you changed the behavior for a single class, what if you need the same logic for other classes? If you need a "generic comparison". That is why you have IEqualityComparer.