Global Exception Handling

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Global Exception Handling
 
Charles Mager




Posts: 39
Joined: 2014-08-06
Hi

I'm developing a Word/Excel add-in, and what I've tried is only in Word at present.

I have a button that ultimately results in an exception being thrown on the Main Thread. I can see this in VS. I'm trying to work out how I catch these exceptions, as they appear to just be swallowed by the framework somewhere. So far I've tried subscribing to the following events:


Application.ThreadException
AppDomain.CurrentDomain.UnhandledException
ADXAddinModule.OnError


I've stuck breakpoints on all three handlers and nothing fires.

Am I missing something?

Thanks

Charlie
Posted 11 Sep, 2014 11:03:17 Top
Andrei Smolin


Add-in Express team


Posts: 17945
Joined: 2006-05-11
Hello Charlie,

You cannot handle exceptions globally in an Office add-in. This is because significant part of the code that your add-in invokes is unmanaged and if an exception occurs in it, there's no way to dispatch/translate the corresponding info so that a managed add-in could handle it.

As to the breakpoints, please check section "Breakpoints are not hit when debugging in Visual Studio" at http://www.add-in-express.com/docs/net-deploying-debugging-tips.php#breakpoints.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 12 Sep, 2014 07:45:20 Top
Charles Mager




Posts: 39
Joined: 2014-08-06
Hi Andrei

Must have been having a long week - of course you're right, I remember this was the case in the VSTO add-ins I've written too for the same reason.

I think the solution I came up with then was to 'decorate' all button click handlers with something like:


public static void Execute(Action action)
{
    try
    {
        action();
    }
    catch (Exception ex)
    {
         //show exception dialog
    }
}


And I'll have to come up with something similar for unhandled exceptions in Word/Excel event handlers. If there's any better approach, please shout!

Re breakpoints - this wasn't quite the issue I was having, I was just explaining that the 'global exception handlers' I tried to add weren't being called. I haven't got any issue debugging in general.

Thanks

Charlie
Posted 14 Sep, 2014 13:42:03 Top
Andrei Smolin


Add-in Express team


Posts: 17945
Joined: 2006-05-11
Hello Charles,

This is a correct approach. Note that Add-in Express wraps raising every event that it provides in a try/catch block; if it encounters an exception, you get the OnError even on the add-in module. A similar approach is used with Add-in Express panes; see the ADXError event provided by the corresponding Manager component: ADXOlFormsManager, ADXExcelTaskPanesManager, etc.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 15 Sep, 2014 02:37:01 Top