ConcurrentDictionary<TKey, TValue>.IDictionary<TKey, TValue>.Add Method

Adds the specified key and value to the IDictionary<TKey, TValue>.

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

void IDictionary<TKey, TValue>.Add(
	TKey key,
	TValue value


Type: TKey

The object to use as the key of the element to add.

Type: TValue

The object to use as the value of the element to add.


IDictionary<TKey, TValue>.Add(TKey, TValue)


key is null.


An element with the same key already exists in the ConcurrentDictionary<TKey, TValue>.


The dictionary already contains the maximum number of elements (MaxValue).

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Windows Phone 8.1, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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