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Dictionary<TKey, TValue>.KeyCollection.ICollection<TKey>.Contains Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Determines whether the ICollection<T> contains a specific value.

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

Syntax

'Declaration
Private Function Contains ( _
    item As TKey _
) As Boolean Implements ICollection(Of TKey).Contains

bool ICollection<TKey>.Contains(
    TKey item
)

Parameters

Return Value

Type: System.Boolean
true if item is found in the ICollection<T>; otherwise, false.

Implements

ICollection<T>.Contains(T)

Remarks

Implementations can vary in how they determine equality of objects; for example, List<T> uses Comparer<T>.Default, whereas, Dictionary<TKey, TValue> allows the user to specify the IComparer<T> implementation to use for comparing keys.

This method is an O(1) operation.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.