Notice (2018-05-24): bugzilla.xamarin.com is now in
Please join us on
Visual Studio Developer Community and in the
Mono organizations on
GitHub to continue tracking issues. Bugzilla will remain
available for reference in read-only mode. We will continue to work
on open Bugzilla bugs, copy them to the new locations
as needed for follow-up, and add the new items under Related
Our sincere thanks to everyone who has contributed on this bug
tracker over the years. Thanks also for your understanding as we
make these adjustments and improvements for the future.
Please create a new report on
Developer Community or GitHub with
your current version information, steps to reproduce, and relevant error
messages or log files if you are hitting an issue that looks similar to
this resolved bug and you do not yet see a matching new report.
1. Page A is on a navigationpage stack.
2. Page A pushes page B onto the navigationpage stack. Page B's constructor subscribes to a message.
3. Page B pushes Page C onto the navigation stack. Page C's OnDisappearing routine sends a message to the subscriber on Page B and pops back to Page B. All good, Page B's message handler is called.
4. Page B pops back to page A. (Page B's destructor unsubscribes, but this seems to be irrelevant.)
5. Steps 2 and 3 are repeated. This time Page B's message handler is called twice, not once as it should be.
Sorry unable atm to provide a simple code example but hopefully straightforward to reproduce.
We'd be happy to help you resolve this issue. Please help us by attaching a reduced reproduction to the bug by starting with a clean Xamarin.Forms project and adding just the code necessary to demonstrate the issue. If you'd do this for us we would very much appreciate it. If you are able to reproduce the issue without modifying the platform specific projects that would eliminate a number of possibilities and likely expedite a resolution.
Xamarin Forms Team
Created attachment 11696 [details]
Minimal code demonstrating the problem
Have attached a minimal sample app BugTest that demonstrates the problem reproducibly.
Place a breakpoint in the GroupsPage message handler then tap the following:
Groups [ Here the breakpoint, correctly, is reached once]
Groups [ Here the breakpoint, incorrectly, is reached twice]
This no longer appears to be occurring with the reproduction as of the latest stable (2.3.3) release.