ToolTipOpening Event

FrameworkElement.ToolTipOpening Event

Updated: May 2010

Occurs when any tooltip on the element is opened.

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

public event ToolTipEventHandler ToolTipOpening
<object ToolTipOpening="ToolTipEventHandler" .../>

Identifier field


Routing strategy




  • Override OnToolTipClosing to implement class handling for this event in derived classes.

To prevent a tooltip from appearing in the UI, your handler for ToolTipOpening can mark the ToolTipEventArgs event data handled. Otherwise, the tooltip is displayed, using the value of the ToolTip property as the tooltip content. Another possible scenario is that you could write a handler that resets the value of the ToolTip property for the element that is the event source, just before the tooltip is displayed.

ToolTipOpening will not be raised if the value of ToolTip is null or otherwise unset. Do not deliberately set ToolTip to null while a tooltip is open or opening; this will not have the effect of closing the tooltip, and will instead create an undesirable visual artifact in the UI.

The ToolTipOpening event cannot be an EventTrigger in a style. This is because the identifier field of this event re-uses an implementation from a service that does not expose add/remove event methods for the service-level event.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0




May 2010

Corrected routed event strategy.

Content bug fix.

Community Additions

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