The default value is false.
When this property is set, if this view starts tracking a touch, no other views in the window will receive these events. Additionally, a view that has set this property to true wont receive any events that are associated with other views in the window.
If a finger touches a view that hast this property set, the event is only delivered if no other view in the window is tracking a finger. If a finger touches a non-exclusive window, the event is only delivered if there are no exclusive views tracking a finger.