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Collection(T).Insert Method

Inserts an element into the Collection(T) at the specified index.

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

public final function Insert(
	index : int, 
	item : T


Type: System.Int32

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

Type: T

The object to insert. The value can be a null reference (Nothing in Visual Basic) for reference types.


IList(T).Insert(Int32, T)


index is less than zero.


index is greater than Count.

Collection(T) accepts a null reference (Nothing in Visual Basic) as a valid value for reference types and allows duplicate elements.

If index is equal to Count, item is added to the end of Collection(T).

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.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0