OrderedDictionary.Keys Property

Definition

Namespace:

System.Collections.Specialized

Assembly:

System.Collections.Specialized.dll

Source:

OrderedDictionary.cs

Gets an ICollection object containing the keys in the OrderedDictionary collection.

public:
 property System::Collections::ICollection ^ Keys { System::Collections::ICollection ^ get(); };

public System.Collections.ICollection Keys { get; }

member this.Keys : System.Collections.ICollection

Public ReadOnly Property Keys As ICollection

Property Value

ICollection

An ICollection object containing the keys in the OrderedDictionary collection.

Implements

Keys

Examples

The following code example demonstrates the creation and population of an OrderedDictionary collection, and then prints the contents to the console. In this example, the Keys and Values properties are passed to a method that displays the contents. This code is part of a larger code example that can be viewed at OrderedDictionary.

// Creates and initializes a OrderedDictionary.
OrderedDictionary^ myOrderedDictionary = gcnew OrderedDictionary();
myOrderedDictionary->Add("testKey1", "testValue1");
myOrderedDictionary->Add("testKey2", "testValue2");
myOrderedDictionary->Add("keyToDelete", "valueToDelete");
myOrderedDictionary->Add("testKey3", "testValue3");

ICollection^ keyCollection = myOrderedDictionary->Keys;
ICollection^ valueCollection = myOrderedDictionary->Values;

// Display the contents using the key and value collections
DisplayContents(keyCollection, valueCollection, myOrderedDictionary->Count);

// Creates and initializes a OrderedDictionary.
OrderedDictionary myOrderedDictionary = new OrderedDictionary();
myOrderedDictionary.Add("testKey1", "testValue1");
myOrderedDictionary.Add("testKey2", "testValue2");
myOrderedDictionary.Add("keyToDelete", "valueToDelete");
myOrderedDictionary.Add("testKey3", "testValue3");

ICollection keyCollection = myOrderedDictionary.Keys;
ICollection valueCollection = myOrderedDictionary.Values;

// Display the contents using the key and value collections
DisplayContents(keyCollection, valueCollection, myOrderedDictionary.Count);

' Creates and initializes a OrderedDictionary.
Dim myOrderedDictionary As New OrderedDictionary()
myOrderedDictionary.Add("testKey1", "testValue1")
myOrderedDictionary.Add("testKey2", "testValue2")
myOrderedDictionary.Add("keyToDelete", "valueToDelete")
myOrderedDictionary.Add("testKey3", "testValue3")

Dim keyCollection As ICollection = myOrderedDictionary.Keys
Dim valueCollection As ICollection = myOrderedDictionary.Values

' Display the contents Imports the key and value collections
DisplayContents( _
    keyCollection, valueCollection, myOrderedDictionary.Count)

// Displays the contents of the OrderedDictionary from its keys and values
static void DisplayContents(
    ICollection^ keyCollection, ICollection^ valueCollection, int dictionarySize)
{
    array<String^>^ myKeys = gcnew array<String^>(dictionarySize);
    array<String^>^ myValues = gcnew array<String^>(dictionarySize);
    keyCollection->CopyTo(myKeys, 0);
    valueCollection->CopyTo(myValues, 0);

    // Displays the contents of the OrderedDictionary
    Console::WriteLine("   INDEX KEY                       VALUE");
    for (int i = 0; i < dictionarySize; i++)
    {
        Console::WriteLine("   {0,-5} {1,-25} {2}",
            i, myKeys[i], myValues[i]);
    }
    Console::WriteLine();
}

// Displays the contents of the OrderedDictionary from its keys and values
public static void DisplayContents(
    ICollection keyCollection, ICollection valueCollection, int dictionarySize)
{
    String[] myKeys = new String[dictionarySize];
    String[] myValues = new String[dictionarySize];
    keyCollection.CopyTo(myKeys, 0);
    valueCollection.CopyTo(myValues, 0);

    // Displays the contents of the OrderedDictionary
    Console.WriteLine("   INDEX KEY                       VALUE");
    for (int i = 0; i < dictionarySize; i++)
    {
        Console.WriteLine("   {0,-5} {1,-25} {2}",
            i, myKeys[i], myValues[i]);
    }
    Console.WriteLine();
}

' Displays the contents of the OrderedDictionary from its keys and values
Public Shared Sub DisplayContents( _
    ByVal keyCollection As ICollection, _
    ByVal valueCollection As ICollection, ByVal dictionarySize As Integer)

    Dim myKeys(dictionarySize) As [String]
    Dim myValues(dictionarySize) As [String]
    keyCollection.CopyTo(myKeys, 0)
    valueCollection.CopyTo(myValues, 0)

    ' Displays the contents of the OrderedDictionary
    Console.WriteLine("   INDEX KEY                       VALUE")
    Dim i As Integer
    For i = 0 To dictionarySize - 1
        Console.WriteLine("   {0,-5} {1,-25} {2}", _
             i, myKeys(i), myValues(i))
    Next i
    Console.WriteLine()
End Sub

Remarks

The returned ICollection object is not a static copy; instead, the ICollection refers back to the keys in the original OrderedDictionary collection. Therefore, changes to the OrderedDictionary continue to be reflected in the ICollection.