The enhanced Excel-specific APIs available for developing Office Add-ins that run with Excel 2016 are a nice start. There are some key missing APIs. One area in need of extending is eventing. For workbooks that contain multiple worksheets, it is critical for the Add-in to be able to determine when a worksheet is activated/deactivated so that the Add-in's UI can adapt accordingly. Similarly, the Office Add-in should be able to hook an event so that when the workbook gets closed/shut down (and maybe Saved), the Add-in can persist in-memory state into the workbook.
Thank you for your request!
We are collecting API requirements for developing Office Add-ins in Excel, specifically for Events API.
If you are considering moving an existing COM/VSTO/VBA Add-in to Office Add-in, or creating a new Office Add-in in Excel, and have events requirements, please fill the survey below and help us focus on the right set of events and design. We truly appreciate your help!
Office Extensibility Team
Shaun Logan commented
I should have put this in the Office.js category