xamarin/Xamarin.Forms

Screen Blinking when adding children dynamically to StackLayout

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#9,048 opened on Dec 30, 2019

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e/6 :clock6:help wantedinactivep/Androidp/iOS 🍎t/bug :bug:up-for-grabs

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Description

Video.zip

Description

When adding children dynamically in StackLayout screen blink before painting the screen.

I have attached the video of production app but attached sample is different. Flickering is happening in video as well as attached sample. Flickering can be noticed at 10 and 19 sec in the video. FlickeringSample.zip

Steps to Reproduce

  1. Run the attached sample
  2. Continuously click on Add Button.
  3. Notice screen flickering after adding the new children.

Expected Behaviour

Elements should not flicker when adding element dynamically.

Actual Behaviour

Screen flickering after adding the new children

Basic Information

  • Version with issue:
  • Last known good version: None
  • IDE: Visual Studio Mac
  • Platform Target Frameworks:
    • iOS: 11.3
    • Android: 10
    • UWP: None
  • Android Support Library Version:
  • Nuget Packages: 4.2
  • Affected Devices: iOS and Android

Screenshots

Video is attached

Reproduction Link

Contributor guide

Research direction
Investigate the layout pass in StackLayout when children are added dynamically. Check for missing or redundant InvalidateMeasure calls causing extra layout cycles.
Tech stack
csharp
Domain
mobile
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
C#Xamarin.Forms
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40