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KeyValuePair<TKey, TValue> Structure

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

Namespace:  System.Collections.Generic
Assembly:  mscorlib (in mscorlib.dll)
[SerializableAttribute]
public struct KeyValuePair<TKey, TValue>

Type Parameters

TKey

The type of the key.

TValue

The type of the value.

The KeyValuePair<TKey, TValue> type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryKeyValuePair<TKey, TValue>Initializes a new instance of the KeyValuePair<TKey, TValue> structure with the specified key and value.
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  NameDescription
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryKeyGets the key in the key/value pair.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryValueGets the value in the key/value pair.
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  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryEqualsIndicates whether this instance and a specified object are equal. (Inherited from ValueType.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetHashCodeReturns the hash code for this instance. (Inherited from ValueType.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryToStringReturns a string representation of the KeyValuePair<TKey, TValue>, using the string representations of the key and value. (Overrides ValueType.ToString().)
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The Dictionary<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<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<TKey, TValue>. For example:


foreach( KeyValuePair<string, string> kvp in myDictionary )
{
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}


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<TKey, TValue> structure.

This code is part of a larger example provided for the Dictionary<TKey, TValue> class.


// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair objects.
Console.WriteLine();
foreach( KeyValuePair<string, string> kvp in openWith )
{
    Console.WriteLine("Key = {0}, Value = {1}", 
        kvp.Key, kvp.Value);
}


.NET Framework

Supported in: 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

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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.
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