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IDictionary.Remove Method

Removes the element with the specified key from the IDictionary object.

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

Sub Remove ( _
	key As Object _
Dim instance As IDictionary
Dim key As Object

void Remove (
	Object key
function Remove (
	key : Object
Not applicable.



The key of the element to remove.

Exception typeCondition


key is a null reference (Nothing in Visual Basic).


The IDictionary object is read-only.


The IDictionary has a fixed size.

If the IDictionary object does not contain an element with the specified key, the IDictionary remains unchanged. No exception is thrown.

The following code example demonstrates how to implement the Remove method. This code example is part of a larger example provided for the IDictionary class.

Public Sub Remove(ByVal key As Object) Implements IDictionary.Remove
    If key = Nothing Then
        Throw New ArgumentNullException("key")
    End If
    ' Try to find the key in the DictionaryEntry array
    Dim index As Integer
    If TryGetIndexOfKey(key, index) Then

        ' If the key is found, slide all the items up.
        Array.Copy(items, index + 1, items, index, (ItemsInUse - index) - 1)
        ItemsInUse = ItemsInUse - 1

        ' If the key is not in the dictionary, just return. 
    End If
End Sub

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.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0