Assembly: PresentationFramework (in PresentationFramework.dll)
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.
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.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.