ConcurrentDictionary<TKey, TValue> Constructor (Int32, Int32, IEqualityComparer<TKey>)

Initializes a new instance of the System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue> class that is empty, has the specified concurrency level, has the specified initial capacity, and uses the specified System.Collections.Generic.IEqualityComparer<T>.

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

public ConcurrentDictionary(
	int concurrencyLevel,
	int capacity,
	IEqualityComparer<TKey> comparer


Type: System.Int32

The estimated number of threads that will update the System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue> concurrently.

Type: System.Int32

The initial number of elements that the System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue> can contain.

Type: System.Collections.Generic.IEqualityComparer<TKey>

The System.Collections.Generic.IEqualityComparer<T> implementation to use when comparing keys.


comparer is null.


concurrencyLevel or capacity is less than 1.

.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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