NameObjectCollectionBase.BaseRemoveAt Method (Int32)
.NET Framework (current version)
Removes the entry at the specified index of the NameObjectCollectionBase instance.
Assembly: System (in System.dll)
Parameters
- index
-
Type:
System.Int32
The zero-based index of the entry to remove.
| Exception | Condition |
|---|---|
| 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.
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 ' 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 'NewNew ' Removes an entry with the specified key from the collection. Overloads Public Sub Remove(key As [String]) Me.BaseRemove(key) End Sub 'Remove ' Removes an entry in the specified index from the collection. Overloads Public Sub Remove(index As Integer) Me.BaseRemoveAt(index) End Sub 'Remove 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) ' 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) 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 '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
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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