Bug 44035 - [UWP] ListView rapid scrolling results in occasional incorrect cell rendering and leaks
Summary: [UWP] ListView rapid scrolling results in occasional incorrect cell rendering...
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 2.3.1
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2016-09-06 19:39 UTC by aculliney
Modified: 2017-08-11 18:41 UTC (History)
4 users (show)

Tags: ac, listview, uwp, memory
Is this bug a regression?: ---
Last known good build:

Image shows glitches in ListView cell colors (4.33 KB, image/png)
2016-09-06 19:45 UTC, aculliney

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Description aculliney 2016-09-06 19:39:39 UTC
We have created a reduced test case project that shows incorrect rendering (and possible leaks) using ListViews with an ItemsSourceProperty binding on Win8.1.

Please see our public repository with the test case : https://bitbucket.org/luminixinc/xamarintest (ListViewsPerfTest branch using the ListViewsPerfTest/ListViewsPerfTest.sln project).


Both tests should be done with Windows 8.1 target (Note that UWP also appears to show the same/similar problems).

Test #1 : Enter the ListView test page and witness that some cells do not correctly draw subsequent colors (R,G,B in that order repeating).  Sometimes a color is repeated or skipped.
    - You may need to return to home page and then re-enter the ListView test page to trigger the behavior
    - Scrolling rapidly top-to-bottom appears to be more likely to trigger the erroneous rendering

Test #2 : Build in release mode and start Debug > Performance Profiler...  Choose 'Memory Usage' and start the diagnostics session.  On the ListView page, aggressively scroll the view top-to-bottom and watch the memory grow (despite bounded number of cells).  Witness what appears to be unbounded memory growth despite GC events during scrolling.
    - Returning to the home page and re-entering ListView test page once does not appear to clear the allocated memory
    - However returning to the home page and re-entering the ListView test page 'a few more times' does appear to clear a significant portion of the allocated memory, but does not appear to clear *all* of it


PullReq improvements/fixes to this test case are most welcome, thanks!
Comment 1 aculliney 2016-09-06 19:45:08 UTC
Created attachment 17354 [details]
Image shows glitches in ListView cell colors

Shows a slice of the ListView with glitches in rendering the R,G,B cells
Comment 2 David Ortinau [MSFT] 2017-08-11 01:16:29 UTC
WP8 and 8.1 have been deprecated and as such this work is no longer on our roadmap.
Comment 3 aculliney 2017-08-11 16:51:07 UTC
Hi David,

The problem still occurs in the UWP build, even after upgrading to the latest Xamarin.Forms stable (

We have refocused our Windows efforts on UWP, so the lingering problem is still a big issue for us.

Please check out our updated project that builds for latest UWP and Xamarin.Forms and continues to exhibit the bug : https://bitbucket.org/luminixinc/xamarintest/branch/ListViewPerfTest

Thank you,