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NameObjectCollectionBase.BaseRemoveAt Method

Removes the entry at the specified index of the NameObjectCollectionBase instance.

Namespace:  System.Collections.Specialized
Assembly:  System (in System.dll)

protected void BaseRemoveAt(
	int index
)

Parameters

index
Type: System.Int32

The zero-based index of the entry to remove.

ExceptionCondition
ArgumentOutOfRangeException

index is outside the valid range of indexes for the collection.

NotSupportedException

The collection is read-only.

In collections of contiguous elements, such as lists, the elements that follow the removed element move up to occupy the vacated spot. If the collection is indexed, the indexes of the elements that are moved are also updated. This behavior does not apply to collections where elements are conceptually grouped into buckets, such as a hash table.

This method is an O(n) operation, where n is Count.

The following code example uses BaseRemove and BaseRemoveAt to remove elements from a NameObjectCollectionBase.

using System;
using System.Collections;
using System.Collections.Specialized;

public class MyCollection : NameObjectCollectionBase  {

   private DictionaryEntry _de = new DictionaryEntry();

   // Gets a key-and-value pair (DictionaryEntry) using an index. 
   public DictionaryEntry this[ int index ]  {
      get  {
         _de.Key = this.BaseGetKey( index );
         _de.Value = this.BaseGet( index );
         return( _de );
      }
   }

   // Adds elements from an IDictionary into the new collection. 
   public MyCollection( IDictionary d )  {
      foreach ( DictionaryEntry de in d )  {
         this.BaseAdd( (String) de.Key, de.Value );
      }
   }

   // Removes an entry with the specified key from the collection. 
   public void Remove( String key )  {
      this.BaseRemove( key );
   }

   // Removes an entry in the specified index from the collection. 
   public void Remove( int index )  {
      this.BaseRemoveAt( index );
   }

}

public class SamplesNameObjectCollectionBase  {

   public static void Main()  {

      // 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}):", myCol.Count );
      PrintKeysAndValues( myCol );

      // Removes an element at a specific index.
      myCol.Remove( 1 );
      Console.WriteLine( "After removing the element at index 1 (Count = {0}):", myCol.Count );
      PrintKeysAndValues( myCol );

      // Removes an element with a specific key.
      myCol.Remove( "red" );
      Console.WriteLine( "After removing the element with the key \"red\" (Count = {0}):", myCol.Count );
      PrintKeysAndValues( myCol );

   }

   public static void PrintKeysAndValues( MyCollection myCol )  {
      for ( int i = 0; i < myCol.Count; i++ )  {
         Console.WriteLine( "[{0}] : {1}, {2}", i, myCol[i].Key, myCol[i].Value );
      }
   }

}


/*
This code produces the following output.

Initial state of the collection (Count = 3):
[0] : red, apple
[1] : yellow, banana
[2] : green, pear
After removing the element at index 1 (Count = 2):
[0] : red, apple
[1] : green, pear
After removing the element with the key "red" (Count = 1):
[0] : green, pear

*/

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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