Windows Dev Center

KeyValuePair<TKey, TValue> Structure

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

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

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 methodKeyValuePair<TKey, TValue>Initializes a new instance of the KeyValuePair<TKey, TValue> structure with the specified key and value.
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  NameDescription
Public propertyKeyGets the key in the key/value pair.
Public propertyValueGets the value in the key/value pair.
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  NameDescription
Public methodEqualsIndicates whether this instance and a specified object are equal. (Inherited from ValueType.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from ValueType.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns 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<int, string> kvp in myDictionary) {...}

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 (the second example) provided for the Dictionary<TKey, TValue> class.


// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair objects.
outputBlock.Text += "\n";
foreach (KeyValuePair<string, string> kvp in openWith)
{
   outputBlock.Text += String.Format("Key = {0}, Value = {1}",
       kvp.Key, kvp.Value) + "\n";
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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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