Bug 46289 - Xamarin iOS 10 WebView freeze after lock / unlock
Summary: Xamarin iOS 10 WebView freeze after lock / unlock
Alias: None
Product: Forms
Classification: Xamarin
Component: iOS ()
Version: 2.3.2
Hardware: Macintosh Mac OS
: --- normal
Target Milestone: ---
Assignee: Paul DiPietro [MSFT]
Depends on:
Reported: 2016-11-02 15:12 UTC by Rafal Grzybowski
Modified: 2017-06-20 13:48 UTC (History)
4 users (show)

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

Sample Xamarin Forms Bug Demo App (13.71 KB, application/zip)
2016-11-02 15:12 UTC, Rafal Grzybowski

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 Rafal Grzybowski 2016-11-02 15:12:19 UTC
Created attachment 18301 [details]
Sample Xamarin Forms Bug Demo App

I have noticed some Xamarin iOS WebView rendering problems after upgrading to iOS 10.

Basically after returning back to the app after screen has been locked and then unlocked causes web view content to freeze. After returning to the app, the user cannot scroll or tap the items on the web view for the most items. The sample attached app uses BBC web site, for this web site, the upper part works more or less fine, the bottom doesn't. But for our internal web site, everything is frozen on iOS 10.

I have reproduced the behaviour only on iOS 10 and cannot reproduce it on the previous iOS version (tested on 9.3.5) or any version on the simulator.

I have attached the sample app that demonstrates the problem.

 - compile the app
 - run the app
 - press Load page and wait till the web site loads
 - lock the device
 - unlock the device
 - on iOS 10 you should observe unresponsive layout
 - on iOS 9.3.5 the web site should work fine


 - OS: macOS 10.12.1
 - Xamarin Studio: 6.1.1 (build 17)
 - Xamarin Forms:
 - Device: iOS 10.1.1

I have created a very similar native iOS app and cannot reproduce the problem.
Comment 1 adrianknight89 2016-11-03 02:53:29 UTC
I could not duplicate your issue with 2.3.3.-pre3. Can you update to the latest and try again?
Comment 2 Rafal Grzybowski 2016-11-03 09:11:31 UTC
I have just retested using Xamarin Forms and it doesn't work as well.

The test was performed on iPad Air 2 and iPad Pro 9.7 both in landscape mode and both running the latest iOS version.

After unlocking the screen, the lower part of the web page (below "News" headline) doesn't react on scrolling and touches.
Comment 3 adrianknight89 2016-11-03 15:13:04 UTC
Ah. Unfortunately, I don't have an iPad, so I will let Xamarin team test this one.
Comment 4 Paul DiPietro [MSFT] 2017-02-27 21:07:17 UTC
I was seemingly only able to reproduce the issue once with the version in the reproduction; I've tried a few times with the latest nightly and can't seem to get it to happen yet on the 10.2 simulator. I don't want to discount the possibility that something is going on so I'm going to set the status of this to needinfo for the time being. Let me know if the newer versions are still posing you any trouble.
Comment 5 Rafal Grzybowski 2017-02-28 07:56:55 UTC
As it was commented, the issue is reproducible mostly on physical device not simulator.
Comment 6 Paul DiPietro [MSFT] 2017-06-20 13:48:38 UTC
We are no longer assuming that this is an issue as it has not been reported by anyone else over the course of a few months. If you're experiencing the issue on the latest prerelease or nightly build, please reopen this with an updated reproduction.