xamarin/Xamarin.Forms

iOS ListView based navigation can crash by updating disposed cells

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#5,542 创建于 2019年3月13日

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a/listviewe/4 :clock4:help wantedi/highinactivep/iOS 🍎t/bug :bug:up-for-grabs

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描述

Description

Binding contexts update stale iOS Views. This causes a crash.

Steps to Reproduce

  1. Use the sample app provided, navigate around and it will crash.

Expected Behavior

Actual Behavior

Basic Information

Stack Trace

System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'CellTableViewCell'.
  at Foundation.NSObject.get_SuperHandle () [0x00012] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/src/Xamarin.iOS/Foundation/NSObject2.cs:449 
  at UIKit.UITableViewCell.get_TextLabel () [0x0002a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/src/Xamarin.iOS/UIKit/UITableViewCell.g.cs:980 
  at Xamarin.Forms.Platform.iOS.TextCellRenderer.HandleCellPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs args) [0x0002a] in <0648e2dffe9e4201b8c6e274ced6579f>:0 
  at Xamarin.Forms.Platform.iOS.CellTableViewCell.HandlePropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e) [0x0000a] in <0648e2dffe9e4201b8c6e274ced6579f>:0 
  at Xamarin.Forms.BindableObject.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:173 
  at Xamarin.Forms.Element.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:339 
  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:622 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00179] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:422 
  at Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System.Boolean fromTarget) [0x00220] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:167 
  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:131 
  at Xamarin.Forms.BindableObject.ApplyBindings (System.Boolean skipBindingContext, System.Boolean fromBindingContextChanged) [0x00041] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:453 
  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:472 
  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:624 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00179] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:422 
  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:572 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:122 
  at Xamarin.Forms.BindableObject.set_BindingContext (System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:26 
  at Xamarin.Forms.Internals.TemplatedItemsList`2[TView,TItem].UnhookItem (TItem item) [0x000a5] in D:\a\1\s\Xamarin.Forms.Core\TemplatedItemsList.cs:1207 
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1023 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/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/12.6.0.25/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/12.6.0.25/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at gMusic.iOS.Application.Main (System.String[] args) [0x00001] in /Users/clancey/Projects/LiveStream/gMusic/gMusic.iOS/Main.cs:17
2019-03-13 15:34:48.689852-0800 gMusic.iOS[25077:820323] 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/12.6.0.25/src/Xamarin.iOS/Foundation/NSObject2.cs:449 
  at UIKit.UITableViewCell.get_TextLabel () [0x0002a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/src/Xamarin.iOS/UIKit/UITableViewCell.g.cs:980 
  at Xamarin.Forms.Platform.iOS.TextCellRenderer.HandleCellPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs args) [0x0002a] in <0648e2dffe9e4201b8c6e274ced6579f>:0 
  at Xamarin.Forms.Platform.iOS.CellTableViewCell.HandlePropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e) [0x0000a] in <0648e2dffe9e4201b8c6e274ced6579f>:0 
  at Xamarin.Forms.BindableObject.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:173 
  at Xamarin.Forms.Element.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:339 
  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:622 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00179] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:422 
  at Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System.Boolean fromTarget) [0x00220] in D:\a\1\s\Xamarin.Forms.Core\BindingExpression.cs:167 
  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:131 
  at Xamarin.Forms.BindableObject.ApplyBindings (System.Boolean skipBindingContext, System.Boolean fromBindingContextChanged) [0x00041] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:453 
  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:472 
  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:624 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00179] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:422 
  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:572 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:122 
  at Xamarin.Forms.BindableObject.set_BindingContext (System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:26 
  at Xamarin.Forms.Internals.TemplatedItemsList`2[TView,TItem].UnhookItem (TItem item) [0x000a5] in D:\a\1\s\Xamarin.Forms.Core\TemplatedItemsList.cs:1207 
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1023 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.6.0.25/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/12.6.0.25/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/12.6.0.25/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at gMusic.iOS.Application.Main (System.String[] args) [0x00001] in /Users/clancey/Projects/LiveStream/gMusic/gMusic.iOS/Main.cs:17

Reproduction Link

https://github.com/clancey/gmusic.forms

贡献者指南

研究方向
调查iOS ListView渲染器中的单元格回收和绑定上下文更新序列，以防止访问已释放的单元格。
技术栈
csharp
领域
mobile dev
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