xamarin/Xamarin.Forms

iOS: System.ObjectDisposedException when ListView bound ObservableCollection is changed

Open

#4,186 opened on Oct 23, 2018

View on GitHubContributor guide
 (19 comments) (1 reaction) (0 assignees)C# (1,926 forks)batch import
3.3.0a/listviewhas-stacktracehelp wantedi/highi/regressionp/iOS 🍎t/bug :bug:up-for-grabs

Repository metrics

Stars
 (5,644 stars)
PR merge metrics
 (No merged PRs in 30d)

Description

Description

when an observable collection, which is bound to a listview is changed (new created with 'new'), the app crashes. this only happens in the ios-app, the android-app is working with no problems.

Steps to Reproduce

i tried to create a minimal project to reproduce the behaviour, but it does not occur. even in our project, the crash is not reproducible all the time. but when it occurs, the stack trace is only in Xamarin.Forms and is always the same:

System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'CellTableViewCell'.
2018-10-23 19:54:27.889451+0200 xxx.iOS[1662:17051] 
Unhandled Exception:
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'CellTableViewCell'.
  at Foundation.NSObject.get_SuperHandle () [0x00012] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:449 
  at UIKit.UITableViewCell.get_TextLabel () [0x0002a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UITableViewCell.g.cs:976 
  at Xamarin.Forms.Platform.iOS.TextCellRenderer.HandleCellPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs args) [0x0002a] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Cells\TextCellRenderer.cs:48 
  at Xamarin.Forms.Platform.iOS.CellTableViewCell.HandlePropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e) [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Cells\CellTableViewCell.cs:44 
  at Xamarin.Forms.BindableObject.OnPropertyChange
d (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:150 
  at Xamarin.Forms.Element.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:370 
  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00114] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:623 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0015b] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:417 
  at Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System
.Boolean fromTarget) [0x00225] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:173 
  at Xamarin.Forms.BindingExpression.Apply (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property) [0x0006b] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:78 
  at Xamarin.Forms.Binding.Apply (System.Object context, Xamarin.Forms.BindableObject bindObj, Xamarin.Forms.BindableProperty targetProperty, System.Boolean fromBindingContextChanged) [0x00057] in D:\a\1\s\Xamarin.Forms.Core\Binding.cs:130 
  at Xamarin.Forms.BindableObject.ApplyBindings (System.Boolean skipBindingContext, System.Boolean fromBindingContextChanged) [0x0003c] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:448 
  at Xamarin.Forms.BindableObject.BindingContextPropertyChanged (Xamarin.Forms.BindableObject bindable, System.Object oldvalue, System.Object newvalue) [0x00007] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:467 
  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableP
roperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00120] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:625 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0015b] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:417 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess) [0x0003d] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:573 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:99 
  at Xamarin.Forms.BindableObject.set_BindingContext (System.Objec
t value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:25 
  at Xamarin.Forms.Internals.TemplatedItemsList`2+<UnhookItem>d__154[TView,TItem].MoveNext () [0x000a5] in D:\a\1\s\Xamarin.Forms.Core\TemplatedItemsList.cs:1207 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSAction.cs:178 
--- End of stack trace from previous location where exception was thrown ---
  at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.Int
Ptr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at xxx.iOS.Application.Main (System.String[] args) [0x00001] in xxx.iOS\Main.cs:12
2018-10-23 19:54:27.892064+0200 xxx.iOS[1662:17051] Unhandled managed exception:
Cannot access a disposed object.
Object name: 'CellTableViewCell'. (System.ObjectDisposedException)
  at Foundation.NSObject.get_SuperHandle () [0x00012] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:449 
  at UIKit.UITableViewCell.get_TextLabel () [0x0002a] in /Libr
ary/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UITableViewCell.g.cs:976 
  at Xamarin.Forms.Platform.iOS.TextCellRenderer.HandleCellPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs args) [0x0002a] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Cells\TextCellRenderer.cs:48 
  at Xamarin.Forms.Platform.iOS.CellTableViewCell.HandlePropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e) [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Cells\CellTableViewCell.cs:44 
  at Xamarin.Forms.BindableObject.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:150 
  at Xamarin.Forms.Element.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:370 
  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean 
currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00114] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:623 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0015b] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:417 
  at Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System.Boolean fromTarget) [0x00225] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:173 
  at Xamarin.Forms.BindingExpression.Apply (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property) [0x0006b] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:78 
  at Xamarin.Forms.Binding.Apply (System.Object context, Xamarin.Forms.BindableObject bindObj, Xamarin.Forms.Bi
ndableProperty targetProperty, System.Boolean fromBindingContextChanged) [0x00057] in D:\a\1\s\Xamarin.Forms.Core\Binding.cs:130 
  at Xamarin.Forms.BindableObject.ApplyBindings (System.Boolean skipBindingContext, System.Boolean fromBindingContextChanged) [0x0003c] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:448 
  at Xamarin.Forms.BindableObject.BindingContextPropertyChanged (Xamarin.Forms.BindableObject bindable, System.Object oldvalue, System.Object newvalue) [0x00007] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:467 
  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00120] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:625 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueF
lags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0015b] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:417 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess) [0x0003d] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:573 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:99 
  at Xamarin.Forms.BindableObject.set_BindingContext (System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:25 
  at Xamarin.Forms.Internals.TemplatedItemsList`2+<UnhookItem>d__154[TView,TItem].MoveNext () [0x000a5] in D:\a\1\s\Xamarin.Forms.Core\TemplatedItemsList.cs:1207 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state
) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSAction.cs:178 
--- End of stack trace from previous location where exception was thrown ---
  at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at xxx.iOS.Application.Main (System.String[] args) [0x00001] in xxx.iOS\Main.cs:12
2018-10-23 19:54:27.893018+0200 xxx.iOS[1662:17051] critical: Stacktrace:
2018-10-23 19:54:27.893300+0200 xxx.iOS[1662:17051] critical: 
Native stacktrace:
2018-10-23 19:54:27.919750+0200 xxx.iOS[1662:17051] critical: 	0   xxx.iOS            0x0000000104780504 mono_handle_native_crash + 244
2018-10-23 19:54:27.920109+0200 xxx.iOS[1662:17051] critical: 	1   libsystem_platform.dylib            0x00000001145b7f5a _sigtramp + 26
2018-10-23 19:54:27.920369+0200 xxx.iOS[1662:17051] critical: 	2   libsystem_pthread.dylib             0x00000001145c6570 libsystem_pthread.dylib + 1392
2018-10-23 19:54:27.920613+0200 xxx.iOS[1662:17051] critical: 	3   libsystem_c.dylib                   0x000000011433fc45 abort + 127
2018-10-23 19:54:27.920880+0200 xxx.iOS[1662:17051] critical: 	4   xxx.iOS            0x000000010499d6af xamarin_unhandled_exception_handler + 47
2018-10-23 19:54:27.921197+0200 xxx.iOS[1662:17051] critical: 	5   xxx.iOS            0x000000010481dece mono_invoke_unhandled_exception_hook + 158
2018-10-23 19:54:27.921474+0200 xxx.iOS[1662:17051] critical: 	6   xxx.iOS            0x000000010477feb8 mono_handle_exception_internal + 5976
2018-10-23 19:54:27.921744+0200 xxx.iOS[1662:17051] critical: 	7   xxx.iOS            0x000000010477e759 mono_handle_exception + 25
2018-10-23 19:54:27.922012+0200 xxx.iOS[1662:17051] critical: 	8   xxx.iOS            0x00000001046fe473 mono_amd64_throw_exception + 131
2018-10-23 19:54:27.922322+0200 xxx.iOS[1662:17051] critical: 	9   ???                                 0x00000001335155a7 0x0 + 5155935655
2018-10-23 19:54:27.922612+0200 xxx.iOS[1662:17051] critical: 	10  xxx.iOS            0x000000010463845c _ZL31native_to_managed_trampoline_20P11objc_objectP13objc_selectorPP11_MonoMethodj + 284
2018-10-23 19:54:27.922877+0200 xxx.iOS[1662:17051] critical: 	11  xxx.iOS            0x000000010463ca04 -[__MonoMac_NSAsyncSynchronizationContextDispatcher xamarinApplySelector] + 52
2018-10-23 19:54:27.923350+0200 xxx.iOS[1662:17051] critical: 	12  Foundation                          0x000000010b0d3e7b __NSThreadPerformPerform + 330
2018-10-23 19:54:27.923874+0200 xxx.iOS[1662:17051] critical: 	13  CoreFoundation                      0x0000000111e52b31 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
2018-10-23 19:54:27.924358+0200 xxx.iOS[1662:17051] critical: 	14  CoreFoundation                      0x0000000111e523a3 __CFRunLoopDoSources0 + 243
2018-10-23 19:54:27.924739+0200 xxx.iOS[1662:17051] critical: 	15  CoreFoundation                      0x0000000111e4ca4f __CFRunLoopRun + 1263
2018-10-23 19:54:27.925236+0200 xxx.iOS[1662:17051] critical: 	16  CoreFoundation                      0x0000000111e4c221 CFRunLoopRunSpecific + 625
2018-10-23 19:54:27.925682+0200 xxx.iOS[1662:17051] critical: 	17  GraphicsServices                    0x00000001183ae1dd GSEventRunModal + 62
2018-10-23 19:54:27.925978+0200 xxx.iOS[1662:17051] critical: 	18  UIKitCore                           0x000000011c5f1115 UIApplicationMain + 140
2018-10-23 19:54:27.926331+0200 xxx.iOS[1662:17051] critical: 	19  ???                                 0x00000001375aef3e 0x0 + 5223673662
2018-10-23 19:54:27.926718+0200 xxx.iOS[1662:17051] critical: 	20  ???                                 0x00000001375aecd3 0x0 + 5223673043
2018-10-23 19:54:27.927111+0200 xxx.iOS[1662:17051] critical: 
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================
The app has been terminated.

Expected Behavior

should not crash

Actual Behavior

Unhandled Exception: System.ObjectDisposedException: Cannot access a disposed object.

Basic Information

  • Version with issue: 3.3.0.91254
  • Last known good version: 3.1.0.697729
  • IDE: visual studio 2017 community
  • Platform Target Frameworks:
    • iOS: 12

Contributor guide

Research direction
Investigate the race condition in TemplatedItemsList.UnhookItem where the cell is disposed before the property changed handler completes. Look at how the cell's BindingContext is set to null and how the cell is recycled. Consider adding a null check or a lock in CellTableViewCell.HandlePropertyChanged.
Tech stack
csharp
Domain
mobile
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.
1-2 days
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
Xamarin.FormsiOS developmentObservableCollectionbinding
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40