Xamarin.forms: [iOS] Crash when creating a CollectionView inside a CollectionView

[MrMayTwenty]

Description

Creating a CollectionView within a CollectionView crashes on iOS

Steps to Reproduce

1. Create a xaml page with a CollectionView inside a CollectionView
2. Create a class for the child containing sample properties
3. Create a class for the parent containing sample properties and a list of the child class
4. Populate the data using Binding
5. Run the app

Expected Behavior

Page is created and CollectionView parent is populated along side the CollectionView child

Actual Behavior

App freezes and throws a message on the application output
* Assertion failure in -[UICollectionView _endItemAnimationsWithInvalidationContext:tentativelyForReordering:animator:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKitCore_Sim/UIKit-3698.103.12/UICollectionView.m:6165

Basic Information

• Version with issue: Xamarin.Forms 4.0.0.497661
• Last known good version:
• IDE: Visual Studio Mac 2019
• Platform Target Frameworks:
  
  
  
  • iOS: 12.2
  
  

[samhouts]

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

[adrianknight89]

What's the use case for nesting CollectionView inside another? We do need to make sure nesting a CarouselView works though.

[istern]

If you have a horizontal list (collectionview) with a vertical list (collectionview) for each entry is something I could see used.
I'm also getting an error for this setup.

I've tested and it is working on Android (emulator) but not on Iphone

[samhouts]

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

[istern]

@samhouts sure https://github.com/istern/CollectionViewBug?files=1 it might not be the most efficient way but I shows the bug

[americofreitasjr]

Just to corroborate with @MrMayTwenty, I'm having a similar problem. Android ok, but in IOS with error.

[Elashi]

I am having the same problem a horizontal collection view inside a vertical collection view. It works in Android but it does not work in iOS. Nothing is displayed.

[ftpps]

I have a similar problem when ListView is hosted in CarouselView via DataTemplate on iOS. any suggestion?

[StevenGranados]

This isn't fixed in 4.2.0. If you try out the repro in the following:
https://github.com/xamarin/Xamarin.Forms/issues/7006
it still crashes on adding a new item.

[StevenGranados]

Also not fixed in the nightly.

[StevenGranados]

Also not fixed in the nightly.

But works in the 4.4.0 nightly now. :)

[EvoPulseGaming]

Sort of the same, using 4.4.0.991210-pre2 on ios 9.3.5
Resolved pending breakpoint at 'NewWorkOrder.xaml.cs:99,1' to void EvoTracker.Pages.NewWorkOrderPage.<>c__DisplayClass12_0.b__0 () [0x00001].
2019-11-17 03:13:18.802 EvoTracker.iOS[203:8301] * Assertion failure in -[UICollectionView _endItemAnimationsWithInvalidationContext:tentativelyForReordering:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3512.60.12/UICollectionView.m:4625

=================================================================

Native Crash Reporting

Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries

used by your application.

=================================================================

Native stacktrace:

0x1bd15e1 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_dump_native_crash_info
0x1bc9c4b - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_handle_native_crash
0x1bd45ab - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_sigsegv_signal_handler_debug
0x210ea077 - /usr/lib/system/libsystem_platform.dylib : _sigtramp
0x1 - Unknown
0x1bc843f - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : unwinder_unwind_frame
0x1bc9387 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_handle_exception_internal
0x1bc8637 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_handle_exception
0x1bc083b - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_arm_throw_exception
0x4e6ba8 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : throw_exception
0x538534 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : ObjCRuntime_Runtime_throw_ns_exception_intptr
0x5ea458 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : wrapper_native_to_managed_ObjCRuntime_Runtime_throw_ns_exception_intptr
0x1cd2944 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : xamarin_throw_ns_exception
0x1cd5918 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : _ZL17exception_handlerP11NSException
0x213bbc57 - /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation : <redacted>
0x20b5709f - /usr/lib/libobjc.A.dylib : <redacted>
0x20b48e17 - /usr/lib/libc++abi.dylib : <redacted>
0x20b488f9 - /usr/lib/libc++abi.dylib : __cxa_increment_exception_refcount
0x20b56f5f - /usr/lib/libobjc.A.dylib : objc_exception_rethrow
0x212cb2af - /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation : CFRunLoopRunSpecific
0x212cb015 - /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation : CFRunLoopRunInMode
0x228bbac9 - /System/Library/PrivateFrameworks/GraphicsServices.framework/GraphicsServices : GSEventRunModal
0x2599f189 - /System/Library/Frameworks/UIKit.framework/UIKit : UIApplicationMain
0x5e8d5c - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : wrapper_managed_to_native_UIKit_UIApplication_UIApplicationMain_int_string___intptr_intptr
0x554688 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : UIKit_UIApplication_Main_string___intptr_intptr
0x55460c - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : UIKit_UIApplication_Main_string___string_string
0x127308 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : EvoTracker_iOS_Application_Main_string__
0x4a9de8 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr
0x1bd7ad3 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_jit_runtime_invoke
0x1c4eceb - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_runtime_invoke_checked
0x1c52c33 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_runtime_exec_main_checked
0x1bc05a9 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : mono_jit_exec
0x1ce78fc - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : xamarin_main
0x1271e1 - /var/containers/Bundle/Application/1CC0232E-C4B6-4CF9-BE87-6BC18F70C880/EvoTracker.iOS.app/EvoTracker.iOS : main
0x20f73873 - /usr/lib/system/libdyld.dylib : <redacted>

=================================================================

Basic Fault Address Reporting

Memory around native instruction pointer (0x1bc7752):0x1bc7742 1c bf da f8 0c 10 88 42 06 d0 b1 6b 81 42 22 bf .......B...k.B".
0x1bc7752 00 68 20 f0 03 00 28 60 d8 f8 04 00
18 b1 c1 7d .h ...(`.......}
0x1bc7762 11 f0 12 0f 3c d0 d8 f8 00 30 00 22 d7 f8 0c a0 ....<....0."....
0x1bc7772 b3 fa 83 f0 41 09 00 20 02 2b 34 46 02 bf 00 23 ....A.. .+4F...#

=================================================================

Managed Stacktrace:

at <0xffffffff>

The app has been terminated.

[EvoPulseGaming]

I was forced to use the 4.4.0 pre2 due to a bug with release version of android, and at the moment this outdated 32bit armv7 device is my testing device.