IList.Insert Method

Inserts an item to the IList at the specified index.

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

void Insert (
	int index,
	T item
void Insert (
	int index, 
	T item
function Insert (
	index : int, 
	item : T
Not applicable.



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


The object to insert into the IList.

Exception typeCondition


index is not a valid index in the IList.


The IList is read-only.

If index equals the number of items in the IList, then item is appended to the list.

In collections of contiguous elements, such as lists, the elements that follow the insertion point move down to accommodate the new element. 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.

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

.NET Compact Framework

Supported in: 2.0

XNA Framework

Supported in: 1.0