CollectionView.IndexOf(Object) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
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
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.