Occurs when the user displays or closes the custom task pane, or when code changes the value of the Visible property.
Assembly: Microsoft.Office.Tools.Common (in Microsoft.Office.Tools.Common.dll)
Microsoft Office applications do not provide a default UI for users to display custom task panes. If you create a custom task pane in your add-in, you should also create a UI element, such as a button, that users can click to display or hide your custom task pane. For more information, see Custom Task Panes.
The following code example demonstrates an event handler for the Walkthrough: Synchronizing a Custom Task Pane with a Ribbon Button.event. This event handler updates the state of a toggle button on the Ribbon whenever the user opens or closes the custom task pane. This code example is part of a larger example provided in