Bug 39768 - PanGestureRecognizer sometimes won't fire completed event when dragging very slowly
Summary: PanGestureRecognizer sometimes won't fire completed event when dragging very ...
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 2.1.0
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
: 60841 60896 ()
Depends on:
Reported: 2016-03-18 17:14 UTC by Paul DiPietro [MSFT]
Modified: 2018-03-26 11:09 UTC (History)
22 users (show)

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

Notice (2018-05-24): bugzilla.xamarin.com is now in read-only mode.

Please join us on Visual Studio Developer Community and in the Xamarin and 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 Links.

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.

Related Links:

Description Paul DiPietro [MSFT] 2016-03-18 17:14:42 UTC
When panning, sometimes the PanGestureRecognizer won't reach its completed state when dragging very slowly. This is noticeable on at least Android, but supposedly occurs on Win 8.1 and WP 8.1.

Project to use, for ease: https://developer.xamarin.com/samples/xamarin-forms/WorkingWithGestures/PanGesture/

To Reproduce:
Add debug logs or breakpoints at the Gesture.Completed case in the PanContainer.cs's OnPanUpdated method.
When running the application, start a pan, hold it for a moment or two, and release.

Expected behavior:
The completed state is reached.

Resulting behavior:
Occasionally/frequently, this state is not reached.
Comment 2 David Stetz 2016-07-08 00:15:00 UTC
I am experiencing this issue as well. Is there a planned fix for this?
Comment 3 Chris Turner 2016-08-07 16:42:53 UTC
I can't believe that this bug has been around so long!!

The recognizer detects GestureStatus.Running without a problem so it sounds like a simple fix to make sure the GestureStatus.Completed state fires the updated event.

Xamarin Forms is a great idea but you cannot leave bugs like this hanging around for months at a time or people will stop developing with it.

Has anyone found a work-around?
Comment 4 Samantha Houts [MSFT] 2016-08-23 00:26:26 UTC
I can't seem to reproduce this for Windows platforms, but I can confirm Android has this issue.
Comment 6 Samantha Houts [MSFT] 2016-10-04 18:59:08 UTC
Should be fixed in 2.3.3-pre3. Thank you!
Comment 7 Parmendra Kumar 2016-11-03 14:41:49 UTC
I have checked this issue with Xamarin.forms 2.3.3-pre3 and observed that this issue has been fixed. I have checked this issue with NexusP (Android 7.0).

Hence closing this issue.
Comment 8 Pavel Sich 2017-07-10 12:35:55 UTC
It is NOT fixed, version 2.3.4 and still easily reproducible on Android 6 and 7.
Comment 9 Richard Pike 2017-11-28 17:10:54 UTC
This bug has come back as of and persists into 2.5.
Reproducible on Android 4.4 and 7
Comment 10 Paul DiPietro [MSFT] 2017-11-28 17:23:38 UTC
*** Bug 60896 has been marked as a duplicate of this bug. ***
Comment 11 Paul DiPietro [MSFT] 2017-11-28 22:40:47 UTC
*** Bug 60841 has been marked as a duplicate of this bug. ***
Comment 12 daspuru 2018-01-02 18:57:30 UTC
Hi all, I hope this bug can be resolved soon... it still happening in these versions:

Xamarin support libraries
Android SDK 26 (8.0)
Comment 13 Paul DiPietro [MSFT] 2018-01-04 02:45:01 UTC
Migrated to https://github.com/xamarin/Xamarin.Forms/issues/1495 for future tracking
Comment 14 Russell Corbin 2018-01-04 05:30:14 UTC
I can confirm this is still an issue on 2.5.0 on Android.
Comment 15 JamesJ 2018-03-07 06:51:42 UTC
Bug still exist.
To reproduce this bug,
Just hold your finger and release after few seconds, which do not fire completed neither cancel.

Any work around?
Comment 16 Marco Rinaldi 2018-03-26 11:09:45 UTC
This seems to be fixed in the release

Good news! :)