Fixing Invalidation Context error for MAUI iOS

[tjvg91]

Hello,

I'm getting this kind of error when running MAUI project for iOS. I'm running on an iOS simulator.

View

<CollectionView ItemsSource="{Binding HundredsList}">
    <CollectionView.ItemsLayout>
		<LinearItemsLayout Orientation="Vertical" />
    </CollectionView.ItemsLayout>
    <CollectionView.ItemTemplate>
        <DataTemplate>
             <Label Text="{Binding Text}"></Label>
        </DataTemplate>
    </CollectionView.ItemTemplate>
</CollectionView>

Model

private ObservableRangeCollection<GridOptions> hundredsList = new ObservableRangeCollection<GridOptions>();
public ObservableRangeCollection<GridOptions> HundredsList
{
     get => hundredsList;
     set
     {
         hundredsList = value;
         SetProperty(ref hundredsList, hundredsList, nameof(HundredsList));
         OnPropertyChanged();
     }
}

private async void InitGrid()
{
     if (HymnInputType == InputType.Grid && !HundredsList.Any())
     {
         await Task.Delay(2000); 
         maxNum = Convert.ToInt32(new Regex("fst").Replace(globalInstance.HymnList[globalInstance.HymnList.Count - 1].Number, ""));
         maxNumString = globalInstance.HymnList[globalInstance.HymnList.Count - 1].Number;
         var totalHundreds = maxNum / 100 + 1;
         for (var i = 0; i < totalHundreds; i++)
         {
             HundredsList.Add(new Models.GridOptions
             {
                 Text = (100 * i + 1) + "-" + Math.Min(100 * (i + 1), maxNum),
                 Val = i
             });
         }
     }
}

Upon adding item to HundredsList collection , I get this error:

"The invalidation context ((null)) sent to -[UICollectionViewFlowLayout invalidateLayoutWithContext:] is not an instance of type UICollectionViewFlowLayoutInvalidationContext or a subclass. Collection view: <UICollectionView: 0x7fc57cd07a00; frame = (0 0; 0 2796); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x600003821f50>; backgroundColor = UIExtendedGrayColorSpace 0 0; layer = <CALayer: 0x600003ca4180>; contentOffset: {0, 0}; contentSize: {0, 0}; adjustedContentInset: {0, 0, 0, 0}; layout: <Microsoft_Maui_Controls_Handlers_Items_ListViewLayout: 0x7fc57db3bcc0>; dataSource: <Microsoft_Maui_Controls_Handlers_Items_ReorderableItemsViewController_1: 0x7fc57bf19dc0>>"

"at ObjCRuntime.Runtime.ThrowException(IntPtr gchandle)\n   at UIKit.UIApplication.UIApplicationMain(Int32 argc, String[] argv, IntPtr principalClassName, IntPtr delegateClassName)\n   at UIKit.UIApplication.Main(String[] args, Type principalClass, Type delegateClass)\n   at MobiHymn_MAUI.Program.Main(String[] args) in /Users/timothyg/Projects/MobiHymn_MAUI/MobiHymn_MAUI/Platforms/iOS/Program.cs:line 13"

Please help not familiar with the error. I can run successfully on Android.

[amiryahaya]

Don't use ObservableRangeCollection use ObservableCollection instead. I don't know why but changing the type fix the issue for me.

[MarcAlx]

To me setting ItemSizingStrategy to ItemSizingStrategy.MeasureFirstItem, prevents this error.

[gacedillo]

This solved the issue for me, thanks @MarcAlx.

[IntegraSysIncJP]

@MarcAlx thanks, worked here also.