Bug 42501 - [WP8] ScrollView Nested in 2+ Layouts Is Not Rendered
Summary: [WP8] ScrollView Nested in 2+ Layouts Is Not Rendered
Status: CONFIRMED
Alias: None
Product: Forms
Classification: Xamarin
Component: Windows ()
Version: 2.3.1
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
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:


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


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Status:
CONFIRMED

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 2.3.0.107 and 2.3.1.111-pre2. This issue started ocurring in Forms 2.1.
Comment 1 Friedrich Wedel 2016-07-18 05:13:56 UTC
I can confirm this bug:
http://forums.xamarin.com/discussion/comment/210138#Comment_210138
Comment 2 Friedrich Wedel 2016-08-08 12:33:18 UTC
Hi

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!