Outlook VSTO Form Region in Add-in Express project

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Outlook VSTO Form Region in Add-in Express project
Nick Williams

Posts: 23
Joined: 2018-03-03

I would like to have a custom icon for my custom MessageClass e.g. IPM.Note.Custom.

I created a test VSTO add-in with a FormRegion and set the Default icon. This works as expected.
I then needed to add the same functionality to my Add-in Express add-in. Add-in Express does not use VSTO FormRegions so this does not appear to be an option? So I tried creating an external manifest XML file and referencing it in the registry. This works, but for some reason the quality of the icon rendering is poor.

I'm using that same icon file with both approaches, but as you can see get differing results. The external manifest icon is on the left, the VSTO FormRegion icon on the right.


The question is, can I use Add-in Express and VSTO within the same add-in? So I can define my FormRegion. Alternatively how can I resolve the icon rendering issue?

Many Thanks
Posted 23 Jun, 2019 04:07:57 Top
Andrei Smolin

Add-in Express team

Posts: 17293
Joined: 2006-05-11
Hello Nick,

You use a Form Region as demonstrated by the sample project at http://temp.add-in-express.com/support/FormRegionTest.zip. The description below may not fully relate to your case; you are expected to customize it so that it works as you expected; say, most probably you'll need to modify the manifest mentioned below.

This approach uses an .OFS file containing an Outlook page, a manifest file specifying the form region creation options, and an image file (a 32x32 .PNG in this case). In event handlers of the form region creation events you pass the page, the manifest, and the image to Outlook. In addition to registering the project, you must also have the registry key below. Note that the setup project also creates this key. Make sure you delete the key when your add-in is unregistered. Here's the registry key:

Key Name: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\FormRegions\IPM.Appointment
Class Name: <NO CLASS>
Last Write Time: 5/18/2017 - 11:51 AM
Value 0
Name: EmptyFormRegion
Type: REG_SZ
Data: =FormRegionTest.AddinModule

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 24 Jun, 2019 04:56:58 Top
Nick Williams

Posts: 23
Joined: 2018-03-03
Thanks Andrei,

I'll check that out, and let you know if I need any more guidance.

Posted 24 Jun, 2019 09:09:21 Top