2 Dakika Kural için C# ReadOnlyCollectionBase Nedir

2 Dakika Kural için C# ReadOnlyCollectionBase Nedir

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To guarantee thread safety during enumeration, you dirilik either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

IEnumerable has been used to represent a read-only collection of data since the earliest versions of .NET. The read-only collection interfaces available in .Safi Core and .Kupkuru 5 enable you to design classes that prevent the collections from being modified.

That method must return an Enumerator object, which provides the actual support for the looping through the collection. Similarly, code that retrieves an item by the item's position in the collection also looks for the IEnumerable interface and uses the GetEnumerator method. What the Enumerator object doesn't support are the Add or Remove methods. Ignoring the ReadOnlyCollectionBase

Elements(IEnumerable) Returns a collection of the child elements of every element and document in the source collection.

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.

Average(IEnumerable, Func) Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.

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.

An immutable object is defined kakım an object that cannot be changed after it has been created. Not all collections are immutable, but you güç use the read-only collection types in .

SkipLast(IEnumerable, Int32) Returns a new enumerable collection that contains the elements from source with the last count elements of the source collection omitted.

In Visual Basic, an extension method must be declared inside a Module and decorated with the Extension attribute. Its first parameter specifies the kind of object to which it will attach itself. I want my extension method to appear in the IntelliSense dropdown lists for any class that implements the IList interface, so I'll declare the method's first (and only) parameter birli IList(of T) -- the compiler will figure out the type that T represents based on the List passed to C# ReadOnlyCollectionBase Nasıl Kullanılır my method.

Descendants(IEnumerable) Returns a collection of elements that contains the descendant elements of every element and document in the source collection.

Bu binanın faydası diziye istediğimiz türden bir nesne atabilme olanakımızdır. Her ne kadar temellangıç değeri, belleği fazladan kullansada boxing nöbetlemi kuruluşlmadığından bu mesabe azıcık azalır. Array derslikı IList arayüzünden türesede Add, Remove, Sort üzere temel metodlara ehil değildir. Hassaten IndexOf, FindIndex kadar indeksleme metodlarını da kullanmaımıza sunmaz. Bu yüzden esnek bir mimariya iye bileğildir. Array dershaneı matris kuruluşsında C# ReadOnlyCollectionBase Kullanımı kullanılan yegane sınıftır.

For maximum flexibility, my class doesn't specify the veri type of the List in which it keeps its actual data. Instead, I declare my UnderlyingList variable to use any class that C# ReadOnlyCollectionBase Kullanımı implements the IList interface. I've also made this a generic class: Rather than specify what kind of List I'm working with, I've forced C# ReadOnlyCollectionBase Nasıl Kullanılır my class to be instantiated with a veri type that the code refers to bey T. Wherever in my code I need to specify my List's veri type, I just use the T C# ReadOnlyCollectionBase Nerelerde Kullanılıyor reference. Finally, I've chosen to have this class implement the generic version of IEnumerable, which requires two versions of the GetEnumerator method -- but the code is identical in both versions of the method. Listing 1. The basics of the PhvReadOnlyList class.

One should note that aku's answer will only protect the list kakım being read only. Elements in the list are still very writable.