NameObjectCollectionBase.BaseGetKey Method
Gets the key of the entry at the specified index of the NameObjectCollectionBase instance.
Assembly: System (in System.dll)
'Declaration Protected Function BaseGetKey ( _ index As Integer _ ) As String 'Usage Dim index As Integer Dim returnValue As String returnValue = Me.BaseGetKey(index)
Parameters
- index
- Type: System.Int32
The zero-based index of the key to get.
Return Value
Type: System.StringA String that represents the key of the entry at the specified index.
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | index is outside the valid range of indexes for the collection. |
The following code example uses BaseGetKey and BaseGet to get specific keys and values.
Imports System Imports System.Collections Imports System.Collections.Specialized Public Class MyCollection Inherits NameObjectCollectionBase Private _de As New DictionaryEntry() ' Gets a key-and-value pair (DictionaryEntry) using an index. Default Public ReadOnly Property Item(index As Integer) As DictionaryEntry Get _de.Key = Me.BaseGetKey(index) _de.Value = Me.BaseGet(index) Return _de End Get End Property ' Gets or sets the value associated with the specified key. Default Public Property Item(key As [String]) As [Object] Get Return Me.BaseGet(key) End Get Set Me.BaseSet(key, value) End Set End Property ' Adds elements from an IDictionary into the new collection. Public Sub New(d As IDictionary) Dim de As DictionaryEntry For Each de In d Me.BaseAdd(CType(de.Key, [String]), de.Value) Next de End Sub 'New End Class 'MyCollection Public Class SamplesNameObjectCollectionBase Public Shared Sub Main() ' Creates and initializes a new MyCollection instance. Dim d = New ListDictionary() d.Add("red", "apple") d.Add("yellow", "banana") d.Add("green", "pear") Dim myCol As New MyCollection(d) Console.WriteLine("Initial state of the collection (Count = {0}):", myCol.Count) PrintKeysAndValues(myCol) ' Gets specific keys and values. Console.WriteLine("The key at index 0 is {0}.", myCol(0).Key) Console.WriteLine("The value at index 0 is {0}.", myCol(0).Value) Console.WriteLine("The value associated with the key ""green"" is {0}.", myCol("green")) End Sub 'Main Public Shared Sub PrintKeysAndValues(myCol As MyCollection) Dim i As Integer For i = 0 To myCol.Count - 1 Console.WriteLine("[{0}] : {1}, {2}", i, myCol(i).Key, myCol(i).Value) Next i End Sub 'PrintKeysAndValues End Class 'SamplesNameObjectCollectionBase 'This code produces the following output. ' 'Initial state of the collection (Count = 3): '[0] : red, apple '[1] : yellow, banana '[2] : green, pear 'The key at index 0 is red. 'The value at index 0 is apple. 'The value associated with the key "green" is pear.
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The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.