Bit of a weird one this: I've got a shared Office addin that currently targets Outlook 2007 on XP and Win7 (Excel/Word and other versions later). It adds a toolbar button, and this fires off my code. My code just reads data from Outlook. First time round, it works a treat. Second time, the button click does nothing. No errors, nothing. The rest of Outlook responds as normal.
The entire event code is in a try/catch that writes any exceptions out to a temporary file (this mechanism works if a throw an exception in code), but nothing is picked up.
According to the "Trust Center", my addin is active (not inactive or disabled). If I restart Outlook, or stop and start the addin via the Trust Center, it again works once and then stops.
If I reduce the amount of work my code does, the button will sometimes respond for about ten clicks or so, then gives up. Whichever version of my code I try, resources don't seem to change much (memory moves up a mite, the thread count stays the same).
I've read of a similar thing with Word, but this was explained by Word recreating the toolbars or menus every time it loads a document (not sure how correct this is). For me, I select an email, click once, it works, click again (no changing views in Outlook, selecting different emails, etc), and it doesn't.
Has anybody got any clues here?
You should place the variable that contains your toolbar buttons to a global scope (You can keep then as fields of the addin object). If you don't keep a valid path to them at all times, .NET garbage collector will eventually clean up these objects and the event handlers with it. This will however not remove the visible button so it will still be visible.