KeyValuePair(Of TKey, TValue) Structure

Defines a key/value pair that can be set or retrieved.

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

'Declaration
<SerializableAttribute> _
Public Structure KeyValuePair(Of TKey, TValue)

Type Parameters

TKey

The type of the key.

TValue

The type of the value.

The KeyValuePair(Of TKey, TValue) type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsKeyValuePair(Of TKey, TValue)Initializes a new instance of the KeyValuePair(Of TKey, TValue) structure with the specified key and value.
Top

  NameDescription
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsKeyGets the key in the key/value pair.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsValueGets the value in the key/value pair.
Top

  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsEqualsIndicates whether this instance and a specified object are equal. (Inherited from ValueType.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetHashCodeReturns the hash code for this instance. (Inherited from ValueType.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsToStringReturns a string representation of the KeyValuePair(Of TKey, TValue), using the string representations of the key and value. (Overrides ValueType.ToString.)
Top

The Dictionary(Of TKey, TValue).Enumerator.Current property returns an instance of this type.

The foreach statement of the C# language (for each in C++, For Each in Visual Basic) requires the type of the elements in the collection. Since each element of a collection based on IDictionary(Of TKey, TValue) is a key/value pair, the element type is not the type of the key or the type of the value. Instead, the element type is KeyValuePair(Of TKey, TValue). For example:

For Each kvp As KeyValuePair(Of String, String) In myDictionary
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp

The foreach statement is a wrapper around the enumerator, which allows only reading from, not writing to, the collection.

The following code example shows how to enumerate the keys and values in a dictionary, using the KeyValuePair(Of TKey, TValue) structure.

This code is part of a larger example provided for the Dictionary(Of TKey, TValue) class.

' When you use foreach to enumerate dictionary elements, 
' the elements are retrieved as KeyValuePair objects.
Console.WriteLine()
For Each kvp As KeyValuePair(Of String, String) In openWith
    Console.WriteLine("Key = {0}, Value = {1}", _
        kvp.Key, kvp.Value)
Next kvp

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

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

Windows Phone 8.1, Windows Phone 8, 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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft