ToolTipService.ToolTipOpeningEvent Field

 

Identifies the ToolTipOpening event that is exposed by objects that use the ToolTipService service to display tooltips.

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

Public Shared ReadOnly ToolTipOpeningEvent As RoutedEvent

Field Value

Type: System.Windows.RoutedEvent

The identifier for the ToolTipOpening event.

The ToolTipOpening event occurs immediately before a tooltip opens. This event does not occur if the tooltip is not defined or if the tooltip content is set to null.

This field registers the behavior of the ToolTipOpening event for classes that use this service. The FrameworkElement and FrameworkContentElement classes both implement the ToolTipService and expose this event through the common language runtime (CLR) accessors FrameworkElement.ToolTipOpening and FrameworkContentElement.ToolTipOpening.

If you specify the tooltip as a ToolTip object, the Opened event is also raised when the tooltip opens.

The following example shows how to set an event handler for the FrameworkElement.ToolTipOpening event. In this case, the event handler is actually for FrameworkElement.ToolTipOpening, because the Ellipse where the handler is attached is a derived class of FrameworkElement.

ellipse2.AddHandler(ToolTipService.ToolTipOpeningEvent, New RoutedEventHandler(AddressOf whenToolTipOpens))
ellipse2.AddHandler(ToolTipService.ToolTipClosingEvent, New RoutedEventHandler(AddressOf whenToolTipCloses))

Private Sub whenToolTipOpens(ByVal sender As Object, ByVal e As RoutedEventArgs)
	Dim ell As New Ellipse()
	If sender.GetType().FullName.Equals("System.Windows.Shapes.Ellipse") Then
		ell = CType(sender, Ellipse)
		ell.Fill = Brushes.Blue
	ElseIf sender.GetType().FullName.Equals("System.Windows.Controls.ToolTip") Then
		Dim t As ToolTip = CType(sender, ToolTip)
		Dim p As Popup = CType(t.Parent, Popup)
		ell = CType(p.PlacementTarget, Ellipse)
		ell.Fill = Brushes.Blue
	End If
End Sub

Private Sub whenToolTipCloses(ByVal sender As Object, ByVal e As RoutedEventArgs)
	Dim ell As New Ellipse()
	If sender.GetType().FullName.Equals("System.Windows.Shapes.Ellipse") Then
		ell = CType(sender, Ellipse)
		ell.Fill = Brushes.Gray
	ElseIf sender.GetType().FullName.Equals("System.Windows.Controls.ToolTip") Then
		Dim t As ToolTip = CType(sender, ToolTip)
		Dim p As Popup = CType(t.Parent, Popup)
		ell = CType(p.PlacementTarget, Ellipse)
		ell.Fill = Brushes.Gray
	End If
End Sub

.NET Framework
Available since 3.0
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