[Bug] Cannot access a disposed object FastRenderers.LabelRenderer

[Transis-Felipe]

JniPeerMembers.AssertSelf (Java.Interop.IJavaPeerable self)
System.ObjectDisposedException: Cannot access a disposed object. Object name: 'Xamarin.Forms.Platform.Android.FastRenderers.LabelRenderer'.CrashVersion 10.1 (200363)

Stack traces
JniPeerMembers.AssertSelf (Java.Interop.IJavaPeerable self)
JniPeerMembers+JniInstanceMethods.InvokeNonvirtualVoidMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters)
TextView.set_TextFormatted (Java.Lang.ICharSequence value)
TextView.set_Text (System.String value)
LabelRenderer.UpdateText ()
LabelRenderer.OnElementPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e)
(wrapper delegate-invoke) .invoke_void_object_PropertyChangedEventArgs(object,System.ComponentModel.PropertyChangedEventArgs)
BindableObject.OnPropertyChanged (System.String propertyName)
Element.OnPropertyChanged (System.String propertyName)
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)
BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes)
BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System.Boolean fromTarget)
BindingExpression.Apply (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property)
Binding.Apply (System.Object context, Xamarin.Forms.BindableObject bindObj, Xamarin.Forms.BindableProperty targetProperty, System.Boolean fromBindingContextChanged)
BindableObject.ApplyBindings (System.Boolean skipBindingContext, System.Boolean fromBindingContextChanged)
BindableObject.SetInheritedBindingContext (Xamarin.Forms.BindableObject bindable, System.Object value)
Element.SetChildInheritedBindingContext (Xamarin.Forms.Element child, System.Object context)
Element.b__78_0 (Xamarin.Forms.BindableObject child, System.Object bc)
BindableObjectExtensions.PropagateBindingContext[T] (Xamarin.Forms.BindableObject self, System.Collections.Generic.IList1[T] children, System.Action2[T1,T2] setChildBindingContext)
Element.OnBindingContextChanged ()
View.OnBindingContextChanged ()
Grid.OnBindingContextChanged ()
BindableObject.SetInheritedBindingContext (Xamarin.Forms.BindableObject bindable, System.Object value)
Element.SetChildInheritedBindingContext (Xamarin.Forms.Element child, System.Object context)
Element.b__78_0 (Xamarin.Forms.BindableObject child, System.Object bc)
BindableObjectExtensions.PropagateBindingContext[T] (Xamarin.Forms.BindableObject self, System.Collections.Generic.IList1[T] children, System.Action2[T1,T2] setChildBindingContext)
Element.OnBindingContextChanged ()
Cell.OnBindingContextChanged ()
BindableObject.BindingContextPropertyChanged (Xamarin.Forms.BindableObject bindable, System.Object oldvalue, System.Object newvalue)
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)
BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes)
BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess)
BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value)
BindableObject.set_BindingContext (System.Object value)
TemplatedItemsList`2[TView,TItem].UnhookItem (TItem item)
AsyncMethodBuilderCore+<>c.b__7_0 (System.Object state)
SyncContext+<>c__DisplayClass2_0.b__0 ()
Thread+RunnableImplementor.Run ()
IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this)
(wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.29(intptr,intptr)

[samhouts]

@transis2 Can you please attach a small project that demonstrates this issue? Thanks!

[Transis-Felipe]

I would like have a repro to help, but I receive this error from a user who Download App from Google Play store.
In my dev machine I never produce this error, but I will try to reproduce it.

[samhouts]

Okay, thank you. We'll keep looking for it.

[jveltd]

We also have this issue but unfortunately no repo to share.

[samhouts]

@transis2 @jveltd Can you share what version of Xamarin.Forms you're using? Are you using formatted text?

[Transis-Felipe]

This bug is related with #6467 (comment)

[PureWeen]

@transis2 and @jveltd can you post a bit of information about the ListView you are using? Maybe the XAML for it? how often are you changing it? does it have a filter? Does the data load from the web?

This issue seems to come from a race condition with the ListView being disposed and the data source on the ListView being changed

Unhook events is being fired after the LabelRenderer attached to the ViewCell but I'm not super sure what would cause this

Unhook seems to only be called when you change the shape of the underlying collection itself and then dispose is only called when the ListView itself is removed from the view tree

so it seems like the ListView is being removed (change of page?) and then at the same time the list attached to the ListView is being modified.

I've tried to trigger the race condition myself but both of those operations seem to happen synchronously so I'm not sure how one would interrupt the other.

On iOS there's a Task.Delay that happens so I could make a guess for iOS but Android doesn't have an await

As a workaround I bet you could set the ITemSource to null on your ListView before navigating away from it or instead of using ObservableCollections just swap out the list when it changes shape opposed to relying on INCC

Though not sure if that would be too expensive for your scenario

We could add a dispose check on UpdateText inside LabelRenderer but I have a feeling that would just move the exception down the road

Or there's a leaked ViewCell somewhere that still has a bindingcontext

[Transis-Felipe]

Hi @PureWeen,
My app is very large and I don't know what is the listview affected.

All my lists binds data locally from sqlite.
I have one that use formattedtext.

What I found after seek into app center common scenarios is that users leave and return a lot before crash.

Some example:
App.OnResume
90 min 17 sec
App.OnSleep
85 min 34 sec
App.OnResume
73 min 6 sec
App.OnSleep
73 min 5 sec
App.OnResume
73 min 3 sec
App.OnSleep
59 min 50 sec

All my listviews have compiled databinding

Here is one of my listviews

                <ListView x:Name="ResultListViewItens" HasUnevenRows="True" ItemAppearing="ResultListViewItens_ItemAppearing" VerticalOptions="FillAndExpand" ItemTapped="ResultListViewItens_ItemTapped" CachingStrategy="RecycleElement" ItemDisappearing="ResultListViewItens_ItemDisappearing" SeparatorVisibility="None">
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <ViewCell.View>
                                    <Grid Padding="5" RowSpacing="3">
                                        <Image Source="{Binding Figura, Mode=OneWay}"  Margin="0,5,0,0" WidthRequest="50" HeightRequest="50" VerticalOptions="Start"/>

                                        <BoxView Color="{DynamicResource SeparatorColor}"  />
                                    </Grid>
                                </ViewCell.View>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>