Xamarin.forms: Xamarin forms 4.2 : After up-gradation, Collection view cells Disappears and Appears when adding items

[vijayMmenlo]

Description

Collection view cells Disappears and Appears when adding items to list. It's like showing blank white space and again adding items.

We are inserting items in middle of the list and it is causing the issue for the first time.

Steps to Reproduce

Expected Behavior

It needs to add smoothly without any existing cells drastic movements.

Actual Behavior

Basic Information

• Version with issue: Xamarin forms 4.2
• Last known good version:
• IDE: Visual Studio Mac
• Platform Target Frameworks:
  
  
  
  • iOS: As of now, facing issue in iOS
  
  

Screenshots

Reproduction Link

[samhouts]

@vijayMmenlo Can you please attach a small project that demonstrates this issue? Thanks!

[vijayMmenlo]

This is client project & policy don't accept to share. I can share below details.
I have used ContextViewCell nuget package to implement swipe with delete functionality. Previously tried with listview with delete(Image), Others options but it is not showing images properly even after applied custom renderer. So we got solution with Collectionview to do so. But Collectionview is not behaving properly after inserting items in middle of the list.

Used below nuget package
https://www.nuget.org/packages/ContextViewCell/

Code for your reference:



























CommandParameter="{Binding .}" />

Please help on this.

[DeanFaizal]

Hey @samhouts please find repro sample attached. Somehow it doesn't happen if I add an item right after creating the ObservableCollection.

TestCollectionViewAdd.zip

[andreabalducci]

Found same issue, if you need another repro: https://github.com/andreabalducci/XamarinCollectionView/blob/b186e563ff8391dfb473e62e5a4c4587e8d4e9da/cvrepro/cvrepro/ListViewModel.cs#L46

[hartez]

7472 is the same issue. Fixed by #7580.