Xamarin.forms: The Xamarin.Forms.CarouselView crashes inside a ListView in iOS only

[ricardouffcomp]

Description

When using the new Xamarin.Forms.CarouselView inside a ListView it throws an exception "System.InvalidCastException: Specified cast is not valid." and the application cannot start. To help to investigate this issue I have developed a very simple app with Xamarin.Forms.CarouselView inside a ListView and it is attached to this ticket.

I am using the latest version of the nightly Xamarin.Forms build: 4.0.1.188134-nightly

Steps to Reproduce

1. Run the attached iOS solution called "App13".
2. The App won't start and it will throw the following exception "System.InvalidCastException: Specified cast is not valid."
3. The app doesn't initialize.

Expected Behavior

The app supposed to display a list view with 6 records and each record contains a Carousel with 3 items (People names).

Actual Behavior

The App won't start and it will throw the following exception "System.InvalidCastException: Specified cast is not valid."

Basic Information

• Version with issue: 4.0.1.188134-nightly
• Last known good version: Since the Xamarin.Forms.CarouselView was introduced in the Xamarin.Forms 4, this CarouselView has never worked with ListView.
• IDE: Visual Studio 15.9.3 Preview 1.0
• Platform Target Frameworks:
  
  
  
  • iOS: 12.2.1.15
  
  
  • Nuget Packages:
  
  
  • Affected Devices:
  
  

Screenshots

The app in iOS supposed to show something like this one in Android:

Reproduction Link

Here is a zip file with a small solution to help to reproduce the issue:

App13.zip

StackTrace

StackTraceBug.txt

[ricardouffcomp]

Hi @samhouts . I noticed this issue was moved to iOS Ready For Work and after that, it was moved back to Triage. Let me know if you need more clarification around this issue.

[samhouts]

@ricardouffcomp We just took it out of the triage board and put it in the Ready for Work board. It's ready for someone to look at! Thanks!

[ricardouffcomp]

Hi @samhouts . Do you know when you are going to have a resource available from the Xamarin Team to work on this issue?

[ricardouffcomp]

Hi @samhouts. I clicked by mistake on the button "Close and Comment"/"Reopen" and the ticket is now sitting in "In Progress" under my name. I am not able to move the ticket back to ToDo. Can you move it back to Todo again? Cheers

[ricardouffcomp]

Hi @samhouts . Are these Xamarin issues being fixed only by the community or there are Microsoft engineers working on these tickets as well? I have reported this bug 2 months ago and it is not clear for me if someone will pick it up soon. It is blocking the release of my app.

[samhouts]

Hi @ricardouffcomp! Microsoft engineers definitely work on these tickets! CarouselView is still in very early preview. We plan to work on it more in the coming sprints. Thank you for your patience!

[jsuarezruiz]

Thanks for the repro sample!. I've been doing tests. I reproduce the same problem with Xamarin.Forms 4.0.1.188134-nightly.

However, I am happy to share that the problem is fixed. If you update the sample to Xamarin.Forms 4.3:

If you update to the latest current version, 4.3.0.819712-pre2, keep in mind that the Layout supported by the CarouselView is LinearItemsLayout.

[ricardouffcomp]

@jsuarezruiz thanks for looking into this issue. I am glad to hear it is fixed now. 😀