Cardview: Binding issue

[robertmiles3]

When I attempt to bind to a property on the main page's view model, it doesn't work. I have created an example here...

https://github.com/robertmiles3/CardsViewBindingIssue

I have your CardsView library as the top example on the MainPage, and I have a CarouselView example below it. I like how your CardsView properly lays out in design mode while CarouselView doesn't layout properly. However, CarouselView properly binds to Stats.Count1 (etc) while I can't get your CardsView to bind like that.

Am I missing something in getting it to bind properly to the Stats property?

[AndreiMisiukevich]

I this case I suggest you to use ItemTemplate property for creating card template. All your cards are the same, but have got different bindingContext

Set ItemTemplate - your view, and Items - Stats collection.
And bind what you want))

[robertmiles3]

Stats isn't a collection. It's a single object with properties on it. How would that work?

[AndreiMisiukevich]

Redesign it to collection of int
new List()

[robertmiles3]

I'm pulling a few counts as stats from a DB, so it doesn't make sense for it to be a list of ints.

[AndreiMisiukevich]

By the way, make this class as IPropertyChanged

public class DashboardStats
{
    public int Count1 { get; set; }
    public int Count2 { get; set; }
    public int Count3 { get; set; }
    public int Count4 { get; set; }

    public int Count5 { get; set; }
    public int Count6 { get; set; }
    public int Count7 { get; set; }
    public int Count8 { get; set; }
}

[AndreiMisiukevich]

And try to call this method first of all

https://github.com/robertmiles3/CardsViewBindingIssue/blob/master/TestCarousel/MainPage.xaml.cs#L32

[robertmiles3]

I had that first at the beginning of my testing. Didn't work, so I moved it around testing different things.

[AndreiMisiukevich]

So, your issue is clear for me, I'll try to help you =) I will look through your code/xaml this weekend

Thank you for feedback

[AndreiMisiukevich]

I think, I know the reason...
Look here https://github.com/AndreiMisiukevich/CardView/blob/master/PanCardView/CardsView.cs#L1068-L1103

if you doesn't use itemTemplate, your view has itself as bindingContext..
It seems like a bug, what do you think, colleague?

[AndreiMisiukevich]

https://github.com/AndreiMisiukevich/CardView/blob/master/PanCardView/CardsView.cs#L1031

if view == context, we needn't set it as context.. maybe it's the reason of our headache)

[AndreiMisiukevich]

Probably, you want to test this case and contribute to this project? Or you can wait until I fix it myself

[robertmiles3]

Hmm, yes possibly so. So, what would be the fix? Can it somehow just use the parent/page binding context?

[AndreiMisiukevich]

I believe if we leave BindingContext as null the view will get parent's context

[robertmiles3]

Gotcha. I'll try that in a bit.

[AndreiMisiukevich]

And it must be here https://github.com/AndreiMisiukevich/CardView/blob/master/PanCardView/CardsView.cs#L526
We should to extend this check

        if (CurrentView.BindingContext == context || CurrentView == context)
        {
            return false;
        }

[AndreiMisiukevich]

So, only two check (the first is above) and the second is below

https://github.com/AndreiMisiukevich/CardView/blob/master/PanCardView/CardsView.cs#L1029

        if (view != null && view != context)
        {
            view.BindingContext = context;
        }

[robertmiles3]

Those 2 changes (L526 and L1029) worked. You want to put those in or want me to submit a PR?

[AndreiMisiukevich]

Create PR please

[AndreiMisiukevich]

I will create new pack on weekend

[ryanherman]

I just ran into this issue where I set the BindingContext to my main view. When I load the CarouselView, it sets it to the main view, then overrides it to the view set.

I was able to temporarily fix this by
protected override void OnParentSet()
{
base.OnParentSet();
Debug.WriteLine("Done");
BindingContext = Navigation.NavigationStack[2];
}

but when you change views, it will reset again.

[AndreiMisiukevich]

Sorry, I didn't understand your matter.

[AndreiMisiukevich]

But it doesn't seem to be the same issue

[AndreiMisiukevich]

@ryanherman I validated all my code and didn't find any line, where I set BindingContext for Carousel/CardsView. I set it only for card elements.

Can you reproduce this issue with latest code?

[AndreiMisiukevich]

https://www.nuget.org/packages/CardsView/1.4.7
pack with fix

[robertmiles3]

Awesome, thanks. Just updated in my main app and it resolved my issue.