NameObjectCollectionBase.BaseGetKey Method
.NET Framework 2.0
Gets the key of the entry at the specified index of the NameObjectCollectionBase instance.
Namespace: System.Collections.Specialized
Assembly: System (in system.dll)
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)
protected String BaseGetKey ( int index )
protected function BaseGetKey ( index : int ) : String
Not applicable.
Parameters
- index
The zero-based index of the key to get.
Return Value
A String that represents the key of the entry at the specified index.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.
import System.* ;
import System.Collections.* ;
import System.Collections.Specialized.* ;
public class MyCollection extends NameObjectCollectionBase
{
private DictionaryEntry _de = new DictionaryEntry();
// Gets a key-and-value pair (DictionaryEntry) using an index.
/** @property
*/
public DictionaryEntry get_Item(int index)
{
_de.set_Key(this.BaseGetKey(index));
_de.set_Value(this.BaseGet(index));
return _de ;
} //get_Item
// Gets or sets the value associated with the specified key.
/** @property
*/
public Object get_Item(String key)
{
return this.BaseGet(key) ;
} //get_Item
/** @property
*/
public void set_Item(String key,Object value )
{
this.BaseSet(key, value);
} //set_Item
//default constructor
public MyCollection()
{
} //MyCollection
// Adds elements from an IDictionary into the new collection.
public MyCollection(IDictionary d)
{
IDictionaryEnumerator objEnum = d.GetEnumerator();
while(objEnum.MoveNext()) {
DictionaryEntry de = (DictionaryEntry)objEnum.get_Current();
this.BaseAdd(((String)(de.get_Key())), de.get_Value());
}
} //MyCollection
} //MyCollection
public class SamplesNameObjectCollectionBase
{
public static void main(String[] args)
{
// Creates and initializes a new MyCollection instance.
IDictionary d = new ListDictionary();
d.Add("red", "apple");
d.Add("yellow", "banana");
d.Add("green", "pear");
MyCollection myCol = new MyCollection(d);
Console.WriteLine("Initial state of the collection (Count = {0}):",
System.Convert.ToString(myCol.get_Count()));
PrintKeysAndValues(myCol);
// Gets specific keys and values.
Console.WriteLine("The key at index 0 is {0}.",
myCol.get_Item( 0).get_Key());
Console.WriteLine("The value at index 0 is {0}.",
myCol.get_Item( 0).get_Value());
Console.WriteLine("The value associated with the key \"green\" is {0}.",
myCol.get_Item( "green"));
} //main
public static void PrintKeysAndValues(MyCollection myCol)
{
for (int i=0 ; i < myCol.get_Count(); i++) {
Console.WriteLine("[{0}] : {1}, {2}", System.Convert.ToString(i),
myCol.get_Item(i).get_Key(), myCol.get_Item(i).get_Value());
}
} //PrintKeysAndValues
} //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.
*/
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.Community Additions
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