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Dictionary(TKey, TValue).KeyCollection Constructor

Dictionary<TKey, TValue>.KeyCollection Constructor

Initializes a new instance of the Dictionary<TKey, TValue>.KeyCollection class that reflects the keys in the specified Dictionary<TKey, TValue>.

Namespace:  System.Collections.Generic
Assemblies:   System.Collections (in System.Collections.dll)
  mscorlib (in mscorlib.dll)

public KeyCollection(
	Dictionary<TKey, TValue> dictionary
)

ExceptionCondition
ArgumentNullException

dictionary is null.

The Dictionary<TKey, TValue>.KeyCollection is not a static copy; instead, the Dictionary<TKey, TValue>.KeyCollection refers back to the keys in the original Dictionary<TKey, TValue>. Therefore, changes to the Dictionary<TKey, TValue> continue to be reflected in the Dictionary<TKey, TValue>.KeyCollection.

This constructor is an O(1) operation.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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