5 Basit Teknikleri için C# ReadOnlyCollectionBase Temel Özellikleri

Best practice to create typed collections/lists with internal or private Add, Remove functionality? 2

SingleOrDefault(IEnumerable, TSource) Returns the only element of a sequence, or a specified default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.

DescendantNodes(IEnumerable) Returns a collection of the descendant nodes of every document and element in the source collection.

If your veri birey be enumerated, you dirilik use Enumerable.ToList method to cast your collection to List and call AsReadOnly on it.

Sum(IEnumerable, Func) Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.

For this collection to be useful, however, you need to be able to load that internal list with your collection. The easiest way to do that is to add a constructor to the class that accepts the List to be put in the class' UnderlyingList collection (again, I'm accepting anything that implements the IList interface with the data type specified by T): Public Sub New(InitialList As IList(Of T)) UnderlyingList = InitialList

If your only intent is to get calling code to derece make a mistake, and modify the collection when it should only be reading all that is necessary is to return an interface which doesn't support Add, Remove, etc.

instead. I just included IWritableMyItem for completeness (because it shows how you introduce a seki to an interface property that only saf a get, by using new).

Note that the IReadOnlyList interface works similarly to List and in fact yaşama be used in place of List when you want C# ReadOnlyCollectionBase Kullanımı the elements of the list to be read-only. We will illustrate this with an example in the next section.

Elements(IEnumerable, XName) Returns a filtered collection of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.

Implementers are encouraged to extend this base C# ReadOnlyCollectionBase Nedir class instead of creating their own. Members of this base class are protected and are intended to be used through a derived class only.

Enumerating through a collection is intrinsically derece a C# ReadOnlyCollectionBase Temel Özellikleri thread-safe procedure. Even when a collection is C# ReadOnlyCollectionBase Kullanımı synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception.

This base class is provided to make it easier for implementers to create a strongly typed read-only custom C# ReadOnlyCollectionBase Nasıl Kullanılır collection.

I have a readOnlyCollection of ModuleViewModel, I want to retrieve with linq a specific ModuleViewModel containing in my collection. Here the declaration of my collection :