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KeyValuePair 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>
generic<typename TKey, typename TValue>
[SerializableAttribute]
public value struct KeyValuePair
[<Sealed>]
[<SerializableAttribute>]
type KeyValuePair<'TKey, 'TValue> = struct end
<SerializableAttribute>
Public Structure KeyValuePair(Of TKey, TValue)

Type Parameters

TKey

The type of the key.

TValue

The type of the value.

NameDescription
System_CAPS_pubmethod KeyValuePair

Initializes a new instance of the KeyValuePair structure with the specified key and value.

NameDescription
System_CAPS_pubproperty

Gets the key in the key/value pair.

System_CAPS_pubproperty

Gets the value in the key/value pair.

NameDescription
System_CAPS_pubmethod Equals

Indicates whether this instance and a specified object are equal.(Inherited from ValueType.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Inherited from ValueType.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethod ToString

Returns a string representation of the KeyValuePair, using the string representations of the key and value.(Overrides ValueTypeToString.)

The property returns an instance of this type.

The foreach statement of the C# language (for each in C++, For Each in Visual Basic) returns an object of the type of the elements in the collection. Since each element of a collection based on IDictionary 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. For example:

foreach( KeyValuePair<string, string> kvp in myDictionary )
{
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
For Each kvp As KeyValuePair(Of String, String) In myDictionary
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp
for each(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 structure.

This code is part of a larger example provided for the Dictionary 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);
}
' 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
// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair objects.
Console::WriteLine();
for each( KeyValuePair<String^, String^> kvp in openWith )
{
    Console::WriteLine("Key = {0}, Value = {1}",
        kvp.Key, kvp.Value);
}
Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

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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