Xamarin.forms: [Bug] CollectionView ChildAdded

[andrewBezerra]

Description

Event ChildAdded on CollectionView don`t fire.

Steps to Reproduce

1. CollectionView with an ItemSource from ViewModel.
2. Add ChildAdded Event
3. On ChildAdded put a DisplayAlert.

Expected Behavior

Display alert on new item added on collectionview.

Actual Behavior

Do notting

Basic Information

• Version with issue: Xamarin.Forms v4.5.0.617
• IDE: Visual Studio 2019

• Platform Target Frameworks:

  • Android: 9

• Nuget Packages: Sharpnado.Presentation.Forms 1.5.1

• Affected Devices: All

GitHub Project

https://github.com/andrewBezerra/Xamarin_TODO

-> MyTasksView.xaml
-> MyTasksView.xaml.cs

[neville-nazerane]

I noticed this too while working with the latest nightly builds. This would be a great bug fix to have.
In case it helps anyone, as a workaround, for now, I just listened for changes in the ItemsSource.

You will need to listen to the property changed of the CarouselView, cast ItemsSource to INotifyCollectionChanged and then subscribe to the CollectionChanged event.

[vniehues]

This is actually huge for some users (myself included).
I used to set alternating row colors for ListViews / BindableLayouts by listening to the ChildAdded event and setting the row color based on an index.
We can't do that anymore and the alternative (templates + selector) is only feasable for "smaller layout" but in my case i got a grid per row with 6 different columns and some GestureRecognizers and in a SwipeView - having this massive piece of XAML twice in one page is just not readable at all.

[Denn1Ro]

Hi,
Any progress of this issue? I am using 4.7.0.1080 and it's still exist.
Thank you.

[vniehues]

@Denn1Ro this here is the link to the corresponding PR https://github.com/xamarin/Xamarin.Forms/pull/10812
To me it looks like there is some good progress happening. I'm waiting aswell...