HybridDictionary.Keys Property
.NET Framework (current version)
Gets an ICollection containing the keys in the HybridDictionary.
Assembly: System (in System.dll)
Property Value
Type: System.Collections.ICollectionAn ICollection containing the keys in the HybridDictionary.
Implements
IDictionary.KeysThe order of the values in the ICollection is unspecified, but it is the same order as the associated values in the ICollection returned by the Values method.
The returned ICollection is not a static copy; instead, the ICollection refers back to the keys in the original HybridDictionary. Therefore, changes to the HybridDictionary continue to be reflected in the ICollection.
Retrieving the value of this property is an O(1) operation.
The following code example enumerates the elements of a HybridDictionary.
Imports System Imports System.Collections Imports System.Collections.Specialized Public Class SamplesHybridDictionary Public Shared Sub Main() ' Creates and initializes a new HybridDictionary. Dim myCol As New HybridDictionary() myCol.Add("Braeburn Apples", "1.49") myCol.Add("Fuji Apples", "1.29") myCol.Add("Gala Apples", "1.49") myCol.Add("Golden Delicious Apples", "1.29") myCol.Add("Granny Smith Apples", "0.89") myCol.Add("Red Delicious Apples", "0.99") myCol.Add("Plantain Bananas", "1.49") myCol.Add("Yellow Bananas", "0.79") myCol.Add("Strawberries", "3.33") myCol.Add("Cranberries", "5.98") myCol.Add("Navel Oranges", "1.29") myCol.Add("Grapes", "1.99") myCol.Add("Honeydew Melon", "0.59") myCol.Add("Seedless Watermelon", "0.49") myCol.Add("Pineapple", "1.49") myCol.Add("Nectarine", "1.99") myCol.Add("Plums", "1.69") myCol.Add("Peaches", "1.99") ' Display the contents of the collection using For Each. This is the preferred method. Console.WriteLine("Displays the elements using For Each:") PrintKeysAndValues1(myCol) ' Display the contents of the collection using the enumerator. Console.WriteLine("Displays the elements using the IDictionaryEnumerator:") PrintKeysAndValues2(myCol) ' Display the contents of the collection using the Keys, Values, Count, and Item properties. Console.WriteLine("Displays the elements using the Keys, Values, Count, and Item properties:") PrintKeysAndValues3(myCol) End Sub 'Main ' Uses the For Each statement which hides the complexity of the enumerator. ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection. Public Shared Sub PrintKeysAndValues1(myCol As IDictionary) Console.WriteLine(" KEY VALUE") Dim de As DictionaryEntry For Each de In myCol Console.WriteLine(" {0,-25} {1}", de.Key, de.Value) Next de Console.WriteLine() End Sub 'PrintKeysAndValues ' Uses the enumerator. ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection. Public Shared Sub PrintKeysAndValues2(myCol As IDictionary) Dim myEnumerator As IDictionaryEnumerator = myCol.GetEnumerator() Console.WriteLine(" KEY VALUE") While myEnumerator.MoveNext() Console.WriteLine(" {0,-25} {1}", myEnumerator.Key, myEnumerator.Value) End While Console.WriteLine() End Sub 'PrintKeysAndValues2 ' Uses the Keys, Values, Count, and Item properties. Public Shared Sub PrintKeysAndValues3(myCol As HybridDictionary) Dim myKeys(myCol.Count) As [String] myCol.Keys.CopyTo(myKeys, 0) Console.WriteLine(" INDEX KEY VALUE") Dim i As Integer For i = 0 To myCol.Count - 1 Console.WriteLine(" {0,-5} {1,-25} {2}", i, myKeys(i), myCol(myKeys(i))) Next i Console.WriteLine() End Sub 'PrintKeysAndValues3 End Class 'SamplesHybridDictionary 'This code produces the following output. ' 'Displays the elements using For Each: ' KEY VALUE ' Seedless Watermelon 0.49 ' Nectarine 1.99 ' Cranberries 5.98 ' Plantain Bananas 1.49 ' Honeydew Melon 0.59 ' Pineapple 1.49 ' Strawberries 3.33 ' Grapes 1.99 ' Braeburn Apples 1.49 ' Peaches 1.99 ' Red Delicious Apples 0.99 ' Golden Delicious Apples 1.29 ' Yellow Bananas 0.79 ' Granny Smith Apples 0.89 ' Gala Apples 1.49 ' Plums 1.69 ' Navel Oranges 1.29 ' Fuji Apples 1.29 ' 'Displays the elements using the IDictionaryEnumerator: ' KEY VALUE ' Seedless Watermelon 0.49 ' Nectarine 1.99 ' Cranberries 5.98 ' Plantain Bananas 1.49 ' Honeydew Melon 0.59 ' Pineapple 1.49 ' Strawberries 3.33 ' Grapes 1.99 ' Braeburn Apples 1.49 ' Peaches 1.99 ' Red Delicious Apples 0.99 ' Golden Delicious Apples 1.29 ' Yellow Bananas 0.79 ' Granny Smith Apples 0.89 ' Gala Apples 1.49 ' Plums 1.69 ' Navel Oranges 1.29 ' Fuji Apples 1.29 ' 'Displays the elements using the Keys, Values, Count, and Item properties: ' INDEX KEY VALUE ' 0 Seedless Watermelon 0.49 ' 1 Nectarine 1.99 ' 2 Cranberries 5.98 ' 3 Plantain Bananas 1.49 ' 4 Honeydew Melon 0.59 ' 5 Pineapple 1.49 ' 6 Strawberries 3.33 ' 7 Grapes 1.99 ' 8 Braeburn Apples 1.49 ' 9 Peaches 1.99 ' 10 Red Delicious Apples 0.99 ' 11 Golden Delicious Apples 1.29 ' 12 Yellow Bananas 0.79 ' 13 Granny Smith Apples 0.89 ' 14 Gala Apples 1.49 ' 15 Plums 1.69 ' 16 Navel Oranges 1.29 ' 17 Fuji Apples 1.29
Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Available since 10
.NET Framework
Available since 1.1
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