CollectionView.IndexOf(Object) CollectionView.IndexOf(Object) CollectionView.IndexOf(Object) CollectionView.IndexOf(Object) Method

Definition

Returns the index at which the specified item is located.

public:
 virtual int IndexOf(System::Object ^ item);
public virtual int IndexOf (object item);
abstract member IndexOf : obj -> int
override this.IndexOf : obj -> int
Public Overridable Function IndexOf (item As Object) As Integer

Parameters

item
Object Object Object Object

The item to locate.

Returns

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

Remarks

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.

Applies to