Occurs when the mouse (or the stylus) leaves the bounding area of a UIElement.
Assembly: System.Windows (in System.Windows.dll)
The event is raised in response to the mouse (or the stylus) leaving the object's bounding area.
You can define multiple events for objects in XAML content. However, if a child object and its parent object both define a event, the parent object's event occurs before the child object's event. This is not a case of a bubbling event; it indicates only that the mouse (or the stylus) has entered both objects, potentially at different times depending on the object layout and composition of the visual tree.
Unlike the MouseEnter event, the event does not provide the mouse (or the stylus) position in event data, because the position of the mouse pointer relative to the object is unknown when it is out of bounds. Because it is always nullNothingnullptrunita null reference (Nothing in Visual Basic), you generally should not use the event data from your event handler, although you may still be interested in the sender parameter.
events do not route, they can only be handled on the element that raises them. For details, see the "MouseEnter and MouseLeave Events" section of Mouse Support.
MouseLeave and OnMouseLeave
Controls that inherit can provide handling for the event that acts as handler for all instances, by overriding the OnMouseLeave method. OnMouseLeave can be useful either for setting visual state, or for public or internal state properties. For instance, Slider implements OnMouseLeave in order to check the Thumb element's value for IsDragging (which cancels a particular behavior mode), and also to set visual state. For more information, see OnMouseLeave.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.