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Cannot access a disposed object. Object name: ScrollViewEx'

Hi, i have sf version 18.1.0.52,  XF version 4.6.0.726.

When I open the pdf page in a navigation page, select "page by page", scroll a couple of pages and then hit the back arrow I get:

Cannot access a disposed object. Object name: ScrollViewEx

"  at Foundation.NSObject.get_SuperHandle () [0x00012] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/Foundation/NSObject2.cs:449 \n  at UIKit.UIView.get_Layer () [0x00025] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/UIView.g.cs:4106 \n  at Syncfusion.SfPdfViewer.XForms.iOS.SfPdfDocumentViewRenderer.Dispose (System.Boolean disposing) [0x00022] in <190e92b52eb24aa688719c2d3ee4a054>:0 \n  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/Foundation/NSObject2.cs:147 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:71 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:39 \n  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementRenderer.cs:365 \n  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/Foundation/NSObject2.cs:147 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:71 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:39 \n  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementRenderer.cs:365 \n  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/Foundation/NSObject2.cs:147 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:71 \n  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementPackager.cs:39 \n  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\VisualElementRenderer.cs:365 \n  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.16.0.13/src/Xamarin.iOS/Foundation/NSObject2.cs:147 \n  at Xamarin.Forms.Platform.iOS.DisposeHelpers.DisposeModalAndChildRenderers (Xamarin.Forms.Element view) [0x00042] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\DisposeHelpers.cs:23 \n  at Xamarin.Forms.Platform.iOS.Platform.HandleChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x00006] in D:\\a\\1\\s\\Xamarin.Forms.Platform.iOS\\Platform.cs:357 \n  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Core\\Element.cs:581 \n  at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x0001f] in D:\\a\\1\\s\\Xamarin.Forms.Core\\Element.cs:339 \n  at Xamarin.Forms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Core\\VisualElement.cs:771 \n  at Xamarin.Forms.Page.OnInternalRemoved (Xamarin.Forms.VisualElement view) [0x00013] in D:\\a\\1\\s\\Xamarin.Forms.Core\\Page.cs:512 \n  at Xamarin.Forms.Page.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0002c] in D:\\a\\1\\s\\Xamarin.Forms.Core\\Page.cs:482 \n  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00018] in /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/src/Xamarin.iOS/external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/ObservableCollection.cs:263 \n  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/src/Xamarin.iOS/external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/ObservableCollection.cs:338 \n  at 
…


I've attached a sample.

Thank you,
Marco

Attachment: HelloWorld_a80b49fe.zip

6 Replies
AV Ashokkumar Viswanathan Syncfusion Team May 14, 2020 08:36 AM UTC

Hi Davide, 
 
Greetings from Syncfusion support, 
 
We were able to reproduce the issue, “Application crashes with object disposed exception in iOS platform”. Currently, we are validating the issue and we will update further details on May 18th , 2020. 
 
Regards, 
Ashok Kumar Viswanathan. 


BV Bob van Schie May 16, 2020 11:16 AM UTC

I experience the same issue; 

AV Ashokkumar Viswanathan Syncfusion Team May 18, 2020 12:10 PM UTC

Hi Davide,   
 
 We have confirmed that the issue “Application crashes with object disposed exception in iOS platform” is defect and logged defect report for this issue. The patch for this issue will be delivered on June 8th , 2020.  
 
Please find the feedback link below, 
  
Regards,  
Ashok Kumar Viswanathan.  


AV Ashokkumar Viswanathan Syncfusion Team June 8, 2020 08:52 AM UTC

Hi Davide,  
  
The issue with “Application crashes with object disposed exception in iOS platform" has been fixed and th patch for this fix can be downloaded from the following location.   
  
Recommended approach - exe will perform automatic configuration 
Please find the patch setup from below location:  
 
  
Advanced approach – use only if you have specific needs and can directly replace existing assemblies for your build environment 
Please find the patch assemblies alone from below location:  

  
NuGet:  
 
Please find the feedback link below,  
 
Assembly Version: 18.1.0.52
Installation Directions :  
This patch should replace the files “Syncfusion.SfPdfViewer.XForms.iOS.dll” under the following folder. 
$system drive:\ Files\Syncfusion\Essential Studio\$Version # \precompiledassemblies\$Version#\4.6 
Eg : $system drive:\Program Files\Syncfusion\Essential Studio\9.3.0.61\precompiledassemblies\9.3.0.61\4.0 
 
To automatically run the Assembly Manager, please check the Run assembly manager checkbox option while installing the patch. If this option is unchecked, the patch will replace the assemblies in precompiled assemblies’ folder only. Then, you will have to manually copy and paste them to the preferred location or you will have to run the Syncfusion Assembly Manager application (available from the Syncfusion Dashboard, installed as a shortcut in the Application menu) to re-install assemblies. 
 
Note :  
You can change how you receive bug fixes by navigating to the following link and updating your preferences. 
 
https://www.syncfusion.com/support/directtrac/patches 
 
Disclaimer :  
Please note that we have created this patch for version 18.1.0.52 specifically to resolve the following issue(s) reported in this/the Forum(s). F154245
If you have received other patches for the same version for other products, please apply all patches in the order received.   

This fix will be included in our 2020 Volume 2 Main Release, which will be available in the month of June 2020.
 
Regards,   
Ashok Kumar Viswanathan.  


DA Dr. Arno Pernozzoli July 6, 2020 09:55 AM UTC

Hi,

I'm experiencing the same issue on version 18.1.0.59.
Is there a patch available for this version?

Regards
Arno

AV Ashokkumar Viswanathan Syncfusion Team July 7, 2020 10:28 AM UTC

Hi Davide, 
We have included the fix for the issue, “Application crashes with object disposed exception in iOS platform” in our 2020 Volume 2 Main Release v18.2.0.44.  
Please find the feedback link for the issue, 
We are glad to announce that our Essential Studio 2020 Volume 2 Main Release v18.2.0.44 is rolled out and is available for download under the following link. 
 
 
We thank you for your support and appreciate your patience in waiting for this release. Please get in touch with us if you would require any further assistance. 
 
Regards, 
Ashok Kumar Viswanathan. 


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