UIElement.MouseEnter Event

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Occurs when the mouse (or a stylus) enters the bounding area of a UIElement.

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


Public Event MouseEnter As MouseEventHandler
public event MouseEventHandler MouseEnter
<uiElement MouseEnter="eventhandler"/>


The MouseEnter event is raised in response to the mouse (or a stylus) moving into the object's bounding area. The MouseEnter event precedes the MouseMove event for the object. The MouseEnter event is not raised if the mouse (or a stylus) did not actually move. For instance, MouseEnter is not raised if the mouse pointer (or the stylus tip) remains stationary, and an object with a MouseEnter handler has its position animated or otherwise adjusted to move under the mouse pointer.

Use a handler based on MouseEventHandler to handle this event. For more information on how to handle mouse events, see Mouse Support.

You can define multiple MouseEnter events for objects in XAML content. However, if a child object and its parent object both define a MouseEnter event, the parent object's MouseEnter event occurs before the child object's MouseEnter event. This is not a case of a bubbling event; it indicates only that the mouse (or stylus) has entered both objects, potentially at different times depending on the layout and the composition of the visual tree.

The mouse position that is reported in the event data may not be exactly on the boundary of the object because of the coalescing of mouse movements.

MouseEnter 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.

MouseEnter and OnMouseEnter

Controls that inherit MouseEnter can provide handling for the event that acts as handler for all instances, by overriding the OnMouseEnter method. OnMouseEnter can be useful either for setting visual state, or for public or internal state properties. For instance, Slider implements OnMouseEnter in order to check the Thumb element's value for IsDragging (which invokes a particular behavior mode), and also to set visual state. For more information, see OnMouseEnter.

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.