How to show screentips and supertips for controls in a contextMenu (XML)

Question

I have created a contextMenu and added a button with the only purpose of displaying a screentip and supertip, while hovering over the button.

<contextMenus>
    <contextMenu idMso="ContextMenuMailItem">
        <button id="TestButton" label="Test" insertAfterMso="Forward" screentip="Screen Tip" supertip="Super Tip"/>
    </contextMenu>
</contextMenus>

However, hovering over the button does not display any screentips or supertips and I'm unsure why that is, since the options to display them are available.

If contextMenus are unable to display tooltips, is Outlook using a different control to display their tooltips?

I know this question is similar to Does Outlook 2010 show screentips and/or supertips for controls added to a contextMenu?. But I cannot find a definitive answer to the question.

Answer 1

The Fluent UI doesn't expose/provide all the features to developers unfortunately. As I wrote earlier, context menu items don't support these properties. You can explore the Fluent UI XML scheme to find what properties are supported or not. On my machine the file is located in the C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\Xml\Schemas\1033 folder which actually depends on the Visual Studio version installed.

Also I'd recommend enabling ribbon UI error messages in the host Office application to make sure no errors are thrown. By default, if a VSTO Add-in attempts to manipulate the Microsoft Office user interface (UI) and fails, no error message is displayed. However, you can configure Microsoft Office applications to display messages for errors that relate to the UI. You can use these messages to help determine why a custom ribbon does not appear, or why a ribbon appears but no controls appear. See How to: Show Add-in user interface errors for more information.