Bug 42501 - [WP8] ScrollView Nested in 2+ Layouts Is Not Rendered
Summary: [WP8] ScrollView Nested in 2+ Layouts Is Not Rendered
Alias: None
Product: Forms
Classification: Xamarin
Component: Windows ()
Version: 2.3.1
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2016-07-12 21:58 UTC by Jimmy [MSFT]
Modified: 2016-08-08 12:33 UTC (History)
4 users (show)

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

repro project (91.63 KB, application/zip)
2016-07-12 21:58 UTC, Jimmy [MSFT]

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 for Bug 42501 on Developer Community or GitHub if you have new information to add and do not yet see a matching new report.

If the latest results still closely match this report, you can use the original description:

  • Export the original title and description: Developer Community HTML or GitHub Markdown
  • Copy the title and description into the new report. Adjust them to be up-to-date if needed.
  • Add your new information.

In special cases on GitHub you might also want the comments: GitHub Markdown with public comments

Related Links:

Description Jimmy [MSFT] 2016-07-12 21:58:56 UTC
Created attachment 16639 [details]
repro project

### Overview
On WP8, controls inside a ScrollView that is nested in 2+ layouts will not be rendered. However, if the ScrollView is empty, then it will be rendered (if it has a Height/WidthRequest). Even more interesting is that if the ScrollView has an (empty) layout, then it will also be rendered. But adding a control to the inner layout will cause the issue again. So it only occurs with control child elements.

I looked into the issue further by creating a custom renderer for the ScrollView and when the issue occurred I observed:

- ArrangeOverride is not called 
- ElementPropertyChanged is not called for ContentSize

### Steps to Reproduce
1. Run the attached project

### Expected Results 
The ScrollView will be rendered.

### Actual Results
The ContentPage is empty.

### Testing Info
Tested on Forms and This issue started ocurring in Forms 2.1.
Comment 1 Friedrich Wedel 2016-07-18 05:13:56 UTC
I can confirm this bug:
Comment 2 Friedrich Wedel 2016-08-08 12:33:18 UTC

In our project we are having a deep hierarchy of controls (also known as control composition). It means a lot of work for us to restructure the complete UI code just because of this bug. Is it possible to handle this bug with high prio or is there a useful workaround?

Thank you!