Bug 42793 - Setting Handled = true in UnhandledException handler has no effect on WinRT 8.1
Summary: Setting Handled = true in UnhandledException handler has no effect on WinRT 8.1
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 2.3.0
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2016-07-25 23:39 UTC by John Hardman
Modified: 2016-08-10 15:55 UTC (History)
3 users (show)

Tags: WinRT 8.1 WinPhone Handled UnhandledException ac
Is this bug a regression?: ---
Last known good build:

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Description John Hardman 2016-07-25 23:39:10 UTC
On Windows platforms (WinRT 8.1, WinPhone RT 8.1, and UWP), I define DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION in the project properties, and then implement my own UnhandledException handler as follows:

            UnhandledException += async (sender, eo) =>
                    eo.Handled = true;

                    Exception ex = eo.Exception as Exception;
                    if (ex != null)

                    // TODO - attempt to use localised text first, but then fallback to hardcoded text if the localised fails
                    MessageDialog md = new MessageDialog(
                        "Something went wrong with the app. Probably best to re-start it as soon as possible.",
                    await md.ShowAsync();
                catch (Exception ex)

Note that InsightsWrapper is just a thin wrapper around Insights/HockeyApp.

On UWP (both 32 and 64 bit builds), the above code does what I would expect, popping up the MessageDialog and waiting for the user to hit the button on the dialog.

However, on WinRT 8.1 and WinPhone RT 8.1, it seems that setting Handled on the exception object has no effect. Despite setting Handled = true, and doing the await, the application closes rather than waiting for the user to respond (and then carrying on as before).