dotnet/winforms

Setting `ListView.CheckBoxes` after `ListView.StateImageList` destroys imagelist

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#3,531 opened on Jul 1, 2020

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:beetle: bug:construction: work in progressarea-controls-ListViewhelp wanted

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Description

  • Have you experienced this same bug with .NET Framework?: Yes

Problem description:

An outcome of investigations in https://github.com/dotnet/winforms/issues/3358, in the following scenarios CheckBoxes is toggled whilst a user-supplied imagelist is bound to StateImageList property - the native listview control will tarnish the user-supplied one.

The issue is reproducible in net4x and netcore3.1.

listview-cb-off

listview-cb-on

Additionally, it appears changes in one instance of listview may affect another, if state imagelist were similar (e.g. contain the same set of images), as the native layer may be caching.

Expected behavior:

Changes CheckBoxes property does no affect a user-supplied imagelist.

Minimal repro:

https://github.com/RussKie/ListViewCheckboxesStateImageList

Also the issue is easily reproducible in .NET Framework designer by setting up the StateImageList property on a ListView control, (save), and then setting CheckBoxes=true.

Contributor guide

Research direction
Investigate how the native ListView control modifies the StateImageList when CheckBoxes is toggled, and find where the user supplied imagelist gets corrupted. Focus on the interactions between the managed wrapper and the underlying Windows common control.
Tech stack
csharp
Domain
desktop
Issue type
Bug
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#Windows FormsGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40