IReadOnlyDictionary<TKey, TValue>.ContainsKey Method

.NET Framework 4.6 and 4.5

Determines whether the read-only dictionary contains an element that has the specified key.

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

bool ContainsKey(
	TKey key
)

Parameters

key
Type: TKey

The key to locate.

Return Value

Type: System.Boolean
true if the read-only dictionary contains an element that has the specified key; otherwise, false.

ExceptionCondition
ArgumentNullException

key is null.

Implementations can vary in how they determine the equality of objects; for example, the class that implements IReadOnlyDictionary<TKey, TValue> might use the Comparer<T>.Default property, or it might implement the IComparer<T> method.

Implementations can vary in whether they allow key to be null.

.NET Framework

Supported in: 4.6, 4.5

.NET for Windows Phone apps

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