ConcurrentDictionary<TKey, TValue>.IDictionary.Add Method

Adds the specified key and value to the dictionary.

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

void IDictionary.Add(
	Object key,
	Object value


Type: System.Object

The object to use as the key.

Type: System.Object

The object to use as the value.


IDictionary.Add(Object, Object)


key is null.


key is of a type that is not assignable to the key type of the System.Collections.Generic.Dictionary<TKey, TValue>.


value is of a type that is not assignable to the type of values in the System.Collections.Generic.Dictionary<TKey, TValue>.


A value with the same key already exists in the Dictionary<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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