Assembly: PresentationCore (in presentationcore.dll)
XML Namespace: http://schemas.microsoft.com/winfx/2006/xaml/presentation
'Declaration Public Event MouseEnter As MouseEventHandler 'Usage Dim instance As UIElement Dim handler As MouseEventHandler AddHandler instance.MouseEnter, handler
/** @event */ public final void add_MouseEnter (MouseEventHandler value) /** @event */ public final void remove_MouseEnter (MouseEventHandler value)
In JScript, you can handle the events defined by a class, but you cannot define your own.
MouseEnter is a routed event that uses the direct event handling routing strategy. Direct routed events are not raised along a route; instead, they are handled in the same element where they are raised. However, they do enable other aspects of routed event behavior, such as event triggers in styles.
Although MouseEnter tracks when the mouse pointer enters the bounds of an element, this event more literally reports that the IsMouseOver property value has changed from false to true on this element.
This event creates an alias for the Mouse.MouseEnter attached event for this class, so that MouseEnter is part of the class members list when UIElement is inherited as a base element. Event handlers that are attached to the MouseEnter event are attached to the underlying Mouse.MouseEnter attached event and receive the same event data instance.
A Button (or any ButtonBase derived class) has native handling for a KeyDown event when the button has focus, and the pressed key is the space bar. The native handling raises the Click event with the button as the source, and also captures the mouse, even though the mouse pointer does not appear to move. As a result of the mouse capture, a MouseEnter event is also raised with the button as the source. In general, if an element captures the mouse, then MouseEnter is raised, as well as GotMouseCapture and possibly other control-specific events.
This example shows how to change the color of an element as the mouse pointer enters and leaves the area occupied by the element.
This example consists of a Extensible Application Markup Language (XAML) file and a code-behind file. For the complete samples, see Mouse Pointer Sample.
<StackPanel> <Border MouseEnter="OnMouseEnterHandler" MouseLeave="OnMouseLeaveHandler" Name="border1" Margin="10" BorderThickness="1" BorderBrush="Black" VerticalAlignment="Center" Width="300" Height="100"> <Label Margin="10" FontSize="14" HorizontalAlignment="Center">Move Cursor Over Me</Label> </Border> </StackPanel>
The following code behind creates the MouseEnter and MouseLeave event handlers. When the mouse pointer enters the Border, the background of the Border is changed to red. When the mouse pointer leaves the Border, the background of the Border is changed back to white.
Partial Public Class Window1 Inherits Window Public Sub New() InitializeComponent() End Sub ' raised when mouse cursor enters the are occupied by the element Sub OnMouseEnterHandler(ByVal sender As Object, ByVal e As MouseEventArgs) border1.Background = Brushes.Red End Sub ' raised when mouse cursor leaves the are occupied by the element Sub OnMouseLeaveHandler(ByVal sender As Object, ByVal e As MouseEventArgs) border1.Background = Brushes.White End Sub End Class
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter EditionThe Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.