Xamarin.forms: [CollectionView/ListView] Not listening for Reset command

Created on 3 Apr 2019 · 11Comments · Source: xamarin/Xamarin.Forms

Description

See issue: https://github.com/jamesmontemagno/mvvm-helpers/issues/39

Basic Information

Xamarin.Forms 3.6.0.264807
Visual Studio 2017 Version 15.9.10
Platforms:
iOS Simulator with iOS 12.1 (iPhone SE)

Reproduction Link

https://github.com/xamadev/ObservableRangeCollectionError

collectionview listview 6 bug

Source

xamadev

Most helpful comment

I am also still having this issue with a collection view. I am using Xamarin.Forms 4.1.0.581479.

Initially the observable collection is empty, then when new data arrives I call Clear and then add the new items.

I have also tried initialising the collection with some items and then calling reset with new items. The initial items display correctly but the new items cause the same error. Here is an Example Repo.

EDIT1: I have tested using the latest pre-release currently available (4.2.0.608146-pre1) and the issue still persists.

afk013 on 19 Jul 2019

👍6

All 11 comments

Not sure if CollectionView supports ObservableRangeCollection.

https://github.com/jamesmontemagno/mvvm-helpers
https://gist.github.com/weitzhandler/65ac9113e31d12e697cb58cd92601091
https://forums.xamarin.com/discussion/29925/observablecollection-addrange

Looks like there is an internal ObservableList<T> with similar functionality.

adrianknight89 on 3 Apr 2019

The same issue with ListView (for ObservableRangeCollection from mvvm-helpers), replacing to ObservableCollection - works correctly.

wcoder on 7 Apr 2019

I get the following error while using ObservableCollection with CollectionView

Objective - C exception thrown. Name: NSInternalInconsistencyException Reason: Invalid update: invalid number of items in section 0.The number of items contained in an existing section after the update(13) must be equal to the number of items contained in that section before the update(13), plus or minus the number of items inserted or deleted from that section (13 inserted, 0 deleted) and plus or minus the number of items moved into or out of that section(0 moved in, 0 moved out).

pfedotovsky on 22 Apr 2019

👍1

@pfedotovsky This error usually happens (on iOS) when items are NOT being added to the underlying adapter/data source on the main thread.

adrianknight89 on 22 Apr 2019

Seems to work just fine on Android, which is interesting......

jamesmontemagno on 27 Apr 2019

😄1

Seems to work just fine on Android, which is interesting......

Oh, I see what y'all are talking about now. Yes, Android does a NotifyDataSetChanged on Reset. Looks like I forgot to call ReloadData on iOS. Fix incoming ...