Cardview: App crashes when the device is rotated and IsViewCachingEnabled = False

[gilbertocarcano]

Hi,
in this very basic example the app stop working when IsViewCacheEnabled="False" and the device (real) is rotated. Thank you for your great work.
cv.txt

[AndreiMisiukevich]

@gilbertocarcano hi, thank you for feedback

    <cards:CarouselView                
        IsViewCacheEnabled="False">
        <cards:CarouselView.ItemsSource>
            <x:Array Type="{x:Type View}">
                <ContentView>
                    <Label Text="11111"></Label>
                </ContentView>
                <ContentView>
                    <Label Text="22222"></Label>
                </ContentView>
            </x:Array>
        </cards:CarouselView.ItemsSource>
        <cards:CarouselView.ItemTemplate>
            <DataTemplate>
                <ContentView>
                    <Frame 
                           VerticalOptions="Center" 
                           HorizontalOptions="Center"
                           HeightRequest="300" 
                           WidthRequest="300"
                           Padding="0"
                           HasShadow="False" 
                           IsClippedToBounds="True" 
                           CornerRadius="10"                            
                           BackgroundColor="#C0C0C0">
                    </Frame>
                </ContentView>
            </DataTemplate>
        </cards:CarouselView.ItemTemplate>
        <controls:LeftArrowControl ToFadeDuration="3000"/>
        <controls:RightArrowControl ToFadeDuration="3000"/>
    </cards:CarouselView>

A little bit strange sample :)
You use views as items source and ItemTemplate :)
And you don't use your views in itemsSource..

Ok, as i understand, i can set ItemsSource any two items array and app will crash with this sample.

Have you got any stacktrace of the crash ?

Is it iOS or Android?

[gilbertocarcano]

Is it Android, I'm not able to test in iOS.
I can't get any staktrace becouse I'm using your plugin as DLL and Visual Studio only says me that there was an exception in the external code.

[AndreiMisiukevich]

Ok, i will try to reproduce

Is there any additional info?
Should i rotate screen during swiping or just open screen with you xaml and rotate device.

Thx

[gilbertocarcano]

Thanks for your response.
The crash happens just opening the screen and rotating the device. I tried IsViewCacheEnabled="True" and the crash go away but this is not an option in my application.

[AndreiMisiukevich]

@gilbertocarcano thanks, i'll check

[gilbertocarcano]

I've downloaded the repo and tried IsViewCacheEnabled ="false" in the CarouselSampleXamlView. The error come from currentViewPair.Value.Clear(), line 492 of CardsView.cs, in the OnSizeChanged() event handler.

[AndreiMisiukevich]

@gilbertocarcano super :) your are right _viewsPool is empty, because caching disabled

Do you want to create PR with fix ?)

            if (CurrentView != null && ItemTemplate != null)
            {
                var currentViewPair = _viewsPool.FirstOrDefault(p => p.Value.Contains(CurrentView));
                if(currentViewPair != null)
                {
                    currentViewPair.Value.Clear();
                    currentViewPair.Value.Add(CurrentView);
                    _viewsPool.Clear();
                   _viewsPool.Add(currentViewPair.Key, currentViewPair.Value);
                }
            }

[AndreiMisiukevich]

@gilbertocarcano it would be awesome if you adjust this fix and test it on your case :)

[gilbertocarcano]

I've tried the fix and it works! The test condition is actually currentViewPair.Value!=null and not currentViewPair!=null
Thank you

[AndreiMisiukevich]

@gilbertocarcano are you going to make PR or I should fix it myself?

[gilbertocarcano]

Sorry, I'didn't understand. I don't know what is a PR so i guess you should fix it yourself. :) I'm going to study how github works asaic :). Good new year!

[AndreiMisiukevich]

@gilbertocarcano ok)