.NET Framework Class Library
CollectionTInsert Method

Inserts an element into the CollectionT at the specified index.

Namespace:   System.Collections.ObjectModel
Assembly:  mscorlib (in mscorlib.dll)
Public Sub Insert ( _
	index As [%$TOPIC/ms132411_en-us_VS_110_2_0_0_0_0%], _
	item As T _
public void Insert(
	[%$TOPIC/ms132411_en-us_VS_110_2_0_1_0_0%] index,
	T item
virtual void Insert(
	[%$TOPIC/ms132411_en-us_VS_110_2_0_2_0_0%] index, 
	T item
) sealed
abstract Insert : 
        index:[%$TOPIC/ms132411_en-us_VS_110_2_0_3_0_0%] * 
        item:'T -> unit  
override Insert : 
        index:[%$TOPIC/ms132411_en-us_VS_110_2_0_3_0_1%] * 
        item:'T -> unit


Type: SystemInt32

The zero-based index at which item should be inserted.

Type: T

The object to insert. The value can be for reference types.


IListTInsert(Int32, T)

index is less than zero.


index is greater than Count.


CollectionT accepts as a valid value for reference types and allows duplicate elements.

If index is equal to Count, item is added to the end of CollectionT.

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

Notes to Inheritors

Derived classes can override InsertItem to change the behavior of this method.

Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, 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.