CollectionView.IndexOf Method (Object)


Returns the index at which the specified item is located.

Namespace:   System.Windows.Data
Assembly:  PresentationFramework (in PresentationFramework.dll)

Public Overridable Function IndexOf (
	item As Object
) As Integer


Type: System.Object

The item to locate.

Return Value

Type: System.Int32

The index at which the specified item is located, or –1 if the item is unknown.

If this method returns an index other than -1, it must always be true that view[index-1] < item <= view[index], where the comparisons are done using the IComparer.Compare method of the view, if one exists.

This particular behavior of the method is used by some CollectionChanged event handlers to speed up reaction to insertion and deletion. If the derived class does not override this method, a listener does a binary search using the IComparer.Compare method.

.NET Framework
Available since 3.0
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