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Syncfusion Feedback

Exception from SfComboBox ios only

Thread ID:





144398 May 4,2019 04:11 PM UTC May 6,2019 12:24 PM UTC Xamarin.Forms 1
Tags: SfComboBox
John Prass
Asked On May 4, 2019 04:20 PM UTC

I'm receiving an null reference exception from SfComboBox when updating an item in the bound ObservableCollection DataSource.  This is working fine in Android, but crashes in ios.  Any help will be greatly appreciated.   I noticed this in, but still see it after upgrading to

Object reference not set to an instance of an object
  at Syncfusion.iOS.ComboBox.SfComboBox.set_DataSource (System.Collections.Generic.IEnumerable`1[T] value) [0x0009d] in <5b131c3053ee491094fa1e7c3a157483>:0 
  at Syncfusion.iOS.ComboBox.SfComboBox.Handle_CollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0000c] in <5b131c3053ee491094fa1e7c3a157483>:0 
  at (wrapper delegate-invoke) .invoke_void_object_NotifyCollectionChangedEventArgs(object,System.Collections.Specialized.NotifyCollectionChangedEventArgs)
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00018] in <1f9da90787fa4aaeae29e27725405a37>:0 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object oldItem, System.Object newItem, System.Int32 index) [0x0000b] in <1f9da90787fa4aaeae29e27725405a37>:0 
  at System.Collections.ObjectModel.ObservableCollection`1[T].SetItem (System.Int32 index, T item) [0x0001c] in <1f9da90787fa4aaeae29e27725405a37>:0 
  at System.Collections.ObjectModel.Collection`1[T].set_Item (System.Int32 index, T value) [0x0002b] in <50aa8c853ba54c99b7836ba4b45a5828>:0 
  at BSMobile.Pages.ContactEditorPage.save_clicked (System.Object sender, System.EventArgs e) [0x00151] in C:\00.Source\BarberShopMobile\BarberShopMobile\BSMobile\BSMobile\Pages\ContactEditorPage.xaml.cs:97 
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/ 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/ 
  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/ 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/ 


Thank you.

Muneesh Kumar G [Syncfusion]
Replied On May 6, 2019 12:24 PM UTC

Hi John Prass, 
Greetings from Syncfusion, we have checked the reported issue "Null reference exception from SfComboBox when updating datasource" and we were unable to reproduce it from our side.  
We have fixed this issue based on provided stack trace detail. Please find the tested sample and custom assemblies from the below link. 
Could you please check the reported issue in provided assembly, if reported issue still persist please provide the modified sample based on your application along with replication procedure. This will be helpful for us to investigate further and provide you a better solution at the earliest. 
Assembly Version:

Please note that we have created this patch for version specifically to resolve the following issue reported in this forum. This fix will be included in our upcoming Volume 1 SP1 release which will be available in the mid of May 2019. 
Muneesh Kumar G. 


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