KeyedCollection(Of TKey, TItem) Constructor
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Initializes a new instance of the KeyedCollection(Of TKey, TItem) class that uses the default equality comparer.
Assembly: mscorlib (in mscorlib.dll)
A KeyedCollection(Of TKey, TItem) created with this constructor uses the default generic equality comparer for the type of the key, obtained from EqualityComparer(Of T).Default. To specify a different generic equality comparer, use the KeyedCollection(Of TKey, TItem)(IEqualityComparer(Of TKey)) constructor or the KeyedCollection(Of TKey, TItem)(IEqualityComparer(Of TKey), Int32) constructor.
By default, the KeyedCollection(Of TKey, TItem) includes a lookup dictionary that is created when the first item is added. When an item is added to the KeyedCollection(Of TKey, TItem), the item's key is extracted once and saved in the lookup dictionary for faster searches. This behavior can be overridden by using the KeyedCollection(Of TKey, TItem)(IEqualityComparer(Of TKey), Int32) constructor and specifying a dictionary creation threshold.
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Because the KeyedCollection(Of TKey, TItem) class is abstract (MustInherit in Visual Basic), you must derive from it in order to use it. In the constructor for your derived type, call the appropriate KeyedCollection(Of TKey, TItem) constructor. It is not necessary to expose functionality like the equality comparer or the dictionary creation threshold in your constructors. |
This constructor is an O(1) operation.
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