Bug 25621 - Xamarin.Forms performs dynamic layout changes poorly compared to 1.2.*.*
Summary: Xamarin.Forms performs dynamic layout changes poorly compared to 1...
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 1.3.0
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2014-12-26 21:31 UTC by Sten
Modified: 2015-02-03 00:49 UTC (History)
4 users (show)

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

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Description Sten 2014-12-26 21:31:34 UTC
Just updated the Xamarin.Forms for a project I started a few days ago and the layout performance is 15 times slower on 1.3 as compared to 1.2.

The layout is essentially this:

    <Labels etc>
    <StackLayout x:Name="dynamicStack">
      <Grid x:Name="addedOnTheFly>
         <Labels etc>
         <StackLayout x:Name="secondDynamicStack">
           <Grid x:Name="item1"/>
           <Grid x:Name="item2"/>

every time anything is added to `secondDynamicStack` it takes ~2 seconds with Xamarin.Forms 1.3 and ~0.08 seconds with 1.2. In my test setup adding 3 items takes 3.6sec vs 0.2 in XF 1.2

I can provide a link to a private git repo upon request
Comment 1 Sten 2014-12-26 23:27:06 UTC
Further notes:
- the grids have some auto-sized rows and * columns.
- the performance degrades more than linearly with the number of nested levels, taking 80 seconds for  3 levels where XF1.2 takes 0.5s but misplaces elements after columns with * width
- there is a weird two-step UI update in XF1.3 where setting item1.IsVisible=false causes item2 to overlap item1 and then item1 disappears after a second or two (see bug text for the named references)
Comment 2 Arpit Jha 2014-12-30 04:52:36 UTC
We have checked this issue and unable to reproduce this issue at our end.
Could you please provide us sample project ,Xamarin.forms  version and build info ,So that we can reproduce  this issue at our end.

You can copy build info from In XS-> About Xamarin studio and copy the info.
Comment 4 Jason Smith [MSFT] 2015-02-03 00:49:15 UTC
This should be resolved in 1.3.3-pre1