Add a button to Outlook message ribbon

Question

I'm totally newbie in Office Add in Development. Started few hours ago :)

Office version: 2016

I would like to create an add-in, with a button that will allow me to synchronize my email with my custom program and "flag" it to avoid a new synchronization in the future. For that, it would be necessary to:

• add a button (it seems simple to me, but by following this link, I did not manage to see the button when debugging in Outlook)
• I would like the button is present in the ribbon that appears when you open an email, and only down (it would prevent a synchronization of several emails at once) - and I can not find the name of the adequate control. There is a list of Excel files (here) but which corresponds to the one of the opening of the mail message?
• perform any action when the user clicks the button - I guess that's a simple event of the button, but how can I get the opened message data and metadata (sender, to, cc, subject ...)
• "flag" the email, so as to avoid a second synchronization. The ideal is to add an icon to the email in the list of emails, as is done for an email containing attachments etc ...

I know I'm asking a lot, but I'm not asking to get the job done, just to be able to steer in the right direction. So if you have tutorials, articles etc ... to help me, it would be great.

Thank you

N.B.: Copy of this question has been posted in VSTO forum here

Answer 1

To create a custom ribbon UI, VSTO provides two possible ways:

• Walkthrough: Create a custom tab by using the Ribbon Designer
• Walkthrough: Create a custom tab by using Ribbon XML

To keep a separate state for the control for each inspector window separately you need to implement ribbon callbacks and call the Invalidate or InvalidateControl methods of the IRibbonUI interface. Read more about these methods in the following articles:

• OfficeTalk: Display and Hide Tabs, Groups, and Controls on the Microsoft Office Ribbon User Interface (Part 1 of 2)
• OfficeTalk: Display and Hide Tabs, Groups, and Controls on the Microsoft Office Ribbon User Interface (Part 2 of 2)

The Fluent UI (aka Ribbon UI) is described in depth:

• Customizing the 2007 Office Fluent Ribbon for Developers (Part 1 of 3)
• Customizing the 2007 Office Fluent Ribbon for Developers (Part 2 of 3)
• Customizing the 2007 Office Fluent Ribbon for Developers (Part 3 of 3)