xamarin/Xamarin.Forms

[Bug] Performance issue with ItemSizingStrategy on CollectionView

Open

#8,314 opened on Oct 30, 2019

View on GitHubContributor guide
 (3 comments) (0 reactions) (0 assignees)C# (1,926 forks)batch import
a/collectionviewa/performancehelp wantedinactivet/bug :bug:up-for-grabs

Repository metrics

Stars
 (5,644 stars)
PR merge metrics
 (No merged PRs in 30d)

Description

Collection view does not add a default ItemSizingStrategy which defaults to MeasureAll.

This causes a major performance hit when using the GridLayout. With 100 items it adds a good 5 seconds to loading. It should default to MeasureFirstItem

Steps to Reproduce

Expected Behavior

Actual Behavior

Basic Information

  • Version with issue:
  • Last known good version:
  • IDE:
  • Platform Target Frameworks:
    • iOS:
    • Android:
    • UWP:
  • Android Support Library Version:
  • Nuget Packages:
  • Affected Devices:

Screenshots

Reproduction Link

Contributor guide

Research direction
Investigate the CollectionView source code to locate where ItemSizingStrategy is set and change the default from MeasureAll to MeasureFirstItem for GridLayout.
Tech stack
csharp
Domain
mobile
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
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#
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50