Outlook 加载时未显示 VSTO 功能区加载项选项卡

Question

I've created an add-in that consist of a ribbon and three tabs. Background to build: The ribbon is built using designer and not xml. The primary use of these is to allow quick opening of various email templates. Tab0 adds a couple buttons to the built in TabMail Tab1 is a new custom tab with various buttons that do various things. Tab2 is a reduced version of Tab1 for use by users of our subsidiary company but pointing to alternatively branded templates. In the coding, Tab1 and Tab2's visibility is set based on user AD group membership on ribbon load event. This has been tested and works. Tab0 always is merged with the built in Home tab shows as expected.

Developers and template admins like me should see all tabs. This also works using same methods.

Current issue: Recently and I think after a certain office 365 update (but not 100% which), Tab1 no longer shows for anyone that should see it on load. However the tab has loaded somewhere. The reason I know this is because to fix this bug all I have to do is minimise the ribbon the re-maximise. Both additional tabs are instantly visible.

Please note, I do not have to disable and the re-enable the actual add-in.

I can also confirm that the Ribbon Type is set correctly (Microsoft.Outlook.Explorer) so please, no reply along those lines either.

I have trawled the web and cannot seem to find an explanation or fix for this behaviour. I'm hoping someone has seen this before and might point me in the right direction.

To replicate, I've seen it happen by just creating a new simple ribbon project and creating a new custom tab. Then create a second tab by copying the first, giving it a diff ID.

eg Ribbon on App Launch/Load - Tab01 Missing

Ribbon on minimise - Tab01 Appears

Ribbon on maximised- Tab01 still visible

Answer 1

Still have no idea why this happens but i have found a work around for those that have experiences the same issue.

The issue seems to affect the first custom tab only. So if you add a new blank custom tab and set its visibility to false, this inherits this bug allowing the other to function properly.

Its a bit of a dirty fix but work well.

Would still be interested in an actual fix if anyone knows one though.

Answer 2

This happens because you had added control to your ribbon perhaps a property to the Control which you should not.

An example is when you add a Ribbon Gallery control to your Ribbon and change its "PositionType" property from Default to another value.

This results in the Ribbon not showing.

Or perhaps you should check the last code you added to your project