Bug 59161 - Previewer exception popup fails to pop up
Summary: Previewer exception popup fails to pop up
Alias: None
Product: Visual Studio Extensions
Classification: Xamarin
Component: Xamarin.Forms Previewer ()
Version: 4.7.0 (15.4)
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Bugzilla
: 59056 59707 ()
Depends on:
Reported: 2017-08-31 22:09 UTC by Bret Johnson [MSFT]
Modified: 2017-09-25 20:49 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

Designer log (57.30 KB, text/plain)
2017-08-31 22:09 UTC, Bret Johnson [MSFT]

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Description Bret Johnson [MSFT] 2017-08-31 22:09:34 UTC
Created attachment 24508 [details]
Designer log

Clone and build the Acquaint sample app: https://github.com/xamarinhq/app-acquaint

For the Debug build, changing the Linking from "Sdk Assemblies Only" to None. That's needed to work around another bug (https://bugzilla.xamarin.com/show_bug.cgi?id=59115)

Open the Previewer on the AcquaintanceEdtPage.xaml
Then open AcquaintanceDetailPage.xaml

Result: You the "An exception occurred while rendering the control" message, with the exclamation icon on the right.  The "Something went wrong / Connection is closed" message is in the body of the preview window.  That's all as expected--there's an error.

But the bug here is that if you click on the red exclamation mark icon, that normally pops up the exception dialog, nothing happens. I think it's more of the previewer getting into a bad state (very quickly) rather than this particular page's error, that causes that. In some other scenarios the exception popup for this page does work.
Comment 1 Bret Johnson [MSFT] 2017-08-31 22:16:34 UTC
See also https://bugzilla.xamarin.com/show_bug.cgi?id=59162, which is another bug for the same scenario.
Comment 2 Alan McGovern 2017-08-31 22:22:52 UTC
All of the exceptions which are related to this error are from the depths of forms itself and not related to the previewer itself. It will probably require change to xamarin.forms or xamarin.android to address.
Comment 3 Alan McGovern 2017-08-31 22:23:34 UTC
*** Bug 59162 has been marked as a duplicate of this bug. ***
Comment 4 Bret Johnson [MSFT] 2017-09-01 00:51:42 UTC
OK, but note that the bug here isn't that there are exceptions, it's that the exception popup is broken.

Sometimes I see the exception popup show, with scrollbars.
Then if I click it again, I'll see it show up--for exactly the same exception--but with no scroll bars (they disappear).
And sometimes I see it not show up at all, like here.

It seems intermittent, but happens a lot. UI resource issue?
Comment 5 Alan McGovern 2017-09-04 13:28:10 UTC
I feel like we can duplicate this one against 59056 because it's talking about the same issue.

The onyl additional request from the other bug was to make the window resizeable, so i'll mention that here.
Comment 6 Alan McGovern 2017-09-04 13:28:19 UTC
*** Bug 59056 has been marked as a duplicate of this bug. ***
Comment 7 Jimmy [MSFT] 2017-09-25 20:49:43 UTC
*** Bug 59707 has been marked as a duplicate of this bug. ***