IList<T>.IndexOf Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Determines the index of a specific item in the IList<T>.

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


Function IndexOf ( _
    item As T _
) As Integer
int IndexOf(
    T item


  • item
    Type: T
    The object to locate in the IList<T>.

Return Value

Type: System.Int32
The index of item if found in the list; otherwise, -1.


If an object occurs multiple times in the list, the IndexOf method always returns the first instance found.

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.