Represents the collection of keys in a
Dictionary. This class cannot be inherited.
Namespace: System.Collections.Generic
Assembly: mscorlib (in mscorlib.dll)
Syntax
Visual Basic (Declaration)
<SerializableAttribute> _
Public NotInheritable Class KeyCollection
Implements ICollection(Of TKey), IEnumerable(Of TKey), _
ICollection, IEnumerable
Dim instance As KeyCollection
[SerializableAttribute]
public sealed class KeyCollection : ICollection<TKey>, IEnumerable<TKey>,
ICollection, IEnumerable
[SerializableAttribute]
public ref class KeyCollection sealed : ICollection<TKey>, IEnumerable<TKey>,
ICollection, IEnumerable
J# supports the use of generic types and methods, but not the declaration of new ones.
JScript does not support generic types and methods.
Remarks
The Dictionary.Keys property returns an instance of this type, containing all the keys in that Dictionary. The order of the keys in the Dictionary.KeyCollection is unspecified, but it is the same order as the associated values in the Dictionary.ValueCollection returned by the Dictionary.Values property.
The Dictionary.KeyCollection is not a static copy; instead, the Dictionary.KeyCollection refers back to the keys in the original Dictionary. Therefore, changes to the Dictionary continue to be reflected in the Dictionary.KeyCollection.
Inheritance Hierarchy
System.Object System.Collections.Generic.Dictionary.KeyCollection
Thread Safety
Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
A Dictionary.KeyCollection can support multiple readers concurrently, as long as the collection is not modified. Even so, enumerating through a collection is intrinsically not a thread-safe procedure. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.
Platforms
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.
Version Information
.NET Framework
Supported in: 3.0, 2.0
.NET Compact Framework
Supported in: 2.0
XNA Framework
Supported in: 1.0
See Also