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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!
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
WP8 and 8.1 have been deprecated and as such this work is no longer on our roadmap.
The problem still occurs in the UWP build, even after upgrading to the latest Xamarin.Forms stable (18.104.22.168)
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