This documentation is archived and is not being maintained.

ListBox.ObjectCollection.IndexOf Method

Returns the index within the collection of the specified item.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public int IndexOf(
	Object value
)

Parameters

value
Type: System.Object
An object representing the item to locate in the collection.

Return Value

Type: System.Int32
The zero-based index where the item is located within the collection; otherwise, negative one (-1).

Implements

IList.IndexOf(Object)

ExceptionCondition
ArgumentNullException

The value parameter is null.

The IndexOf method enables you to determine where an item is located within the collection. To determine whether an item is located within the collection before calling this method, use the Contains method.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Show: