Bug 60436 - Label height not refreshed (only when: delayed text update, Android 4.0.3, NavigationPage, ScrollView, StackLayout)
Summary: Label height not refreshed (only when: delayed text update, Android 4.0.3, Na...
Alias: None
Product: Forms
Classification: Xamarin
Component: Android ()
Version: 2.5.0
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2017-10-30 15:17 UTC by Milan Laslop
Modified: 2018-02-12 18:25 UTC (History)
6 users (show)

Tags: label, height, pre-appcompat, ac
Is this bug a regression?: ---
Last known good build:

test project (53.06 KB, application/x-zip-compressed)
2017-10-30 15:17 UTC, Milan Laslop

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Description Milan Laslop 2017-10-30 15:17:07 UTC
Created attachment 25504 [details]
test project

- see attachments - xamarin_forms_label_test.zip
- run the app on Android 4.0.3 or 4.1.2 (the 4.1.2 emulator from Android SDK works for sure)
- click Go To Next Page
- two lines of text appear (line1, line2)
- background task waits 7 seconds, then updates Label - adds line3
- problem: line3 is not shown (height of Label is not recalculated)

Can be reproduced with Xamarin Forms and Xamarin Forms

Exactly these conditions must be met for it to be reproducible:
- must be Android 4.0.3 or 4.1.2, maybe some newer, but not e.g. 7.1.1 (on 7.1.1, it works correctly)
- Label must be in ScrollView and then StackLayout - leaving out ScrollView or StackLayout causes correct behavior
- we must update the Label text later, not directly in Page2 constructor (as you can see, constructor adds 2 lines (line1 and line2) and the height is calculated correctly here)
- Page2 has to be pushed to stack of a NavigationPage - it works correctly if Page2 is directly passed to constructor of NavigationPage as the root page (that's why there is Page1 with the big button)
Comment 1 Paul DiPietro [MSFT] 2017-11-07 18:38:56 UTC
Occurred on a 4.2.2 emulator as well; will set to confirmed until further investigation can be made.
Comment 2 Luiz Arantes Sa 2017-12-06 16:56:58 UTC
I'm also experiencing this issue. Labels sometimes won't render at all and it's only happening in Android 4.1. I had to downgrade to Xamarin.Forms 2.3 to get things workings again.
Comment 3 Luiz Arantes Sa 2017-12-06 17:09:51 UTC
Tested on Android 4.1.2:
- Works in Xamarin.Forms.
- Broken in Xamarin.Forms.
Comment 4 Lukáš Novotný 2017-12-08 15:30:42 UTC
This is very likely duplicate of https://bugzilla.xamarin.com/show_bug.cgi?id=60155
Comment 5 Samantha Houts [MSFT] 2018-02-12 18:25:53 UTC
This issue has been migrated to https://github.com/xamarin/Xamarin.Forms/issues/1332. Please follow that issue for updates. Thanks!