Compatibility with ReactiveUI bindings

[grounch]

Hi

Not sure if it's really a bug of your plugin or a conflict with reactiveui.

I'm implementing design for an existing xamarin app using reactiveui.
The problem is to handle bindings. When this way of binding was working before

Code behind of xaml

InitializeComponent();

this.WhenActivated(disposables =>
{
     this.Bind(ViewModel, vm => vm.knob, v => v.slidertest.SliderValue,
                    vmToViewConverter: v => (float)v, viewToVmConverter: v => (byte)v)
                    .DisposeWith(disposables);
}

it returns the error "Operation is not valid due to the current state of the object" once the slider is placed in a carouselview containing few ContentView

Simplified xaml looks like that:

      <core:CarouselView >
           <x:Arguments>
               <proc:CarouselProcessor OpacityFactor="-0.5"/>
           </x:Arguments>

   	<core:CarouselView.ItemsSource>
   		<x:Array Type="{x:Type ContentView}">

   			<ContentView >
                                     <Label Text="nothing"/>
                               </ContentView>

                              <ContentView>

                              <core:SliderView x:Name="slidertest"
                                                           Padding="30,0"/>

                             </ContentView>
   		</x:Array>
		</core:CarouselView.ItemsSource>

           <controls:Indicators  SelectedIndicatorStyle="{StaticResource ActiveIndicator}"
                                 UnselectedIndicatorStyle="{StaticResource InactiveIndicator}"/>
           <controls:LeftArrow ImageSource="arrow_left_grey" WidthRequest="12" HeightRequest="20"/>
           <controls:RightArrow ImageSource="arrow_right_grey" WidthRequest="12" HeightRequest="20"/>

</core:CarouselView>

If i take out the SliderView from the CarouselView it works fine.
Doesn't come from my custom control as i tried with simple elements like labels and i get the same behavior.

Not being a big fan myself of all this reactiveui messy bindings and commands, but redesigning the whole app code isn't really an option.
Did you had any similar reported issues?
The issue probably comes from the late initialization of the contentviews, happening after the reactiveui bindings. So it tries to bind to a not existing yet "slidertest"
Is there a way in code behind to make them load earlier as workaround? Before this.WhenActivated for example

Thanks

[grounch]

I think it's definitely an init timing issue.
If i put this in the code behind:

InitializeComponent();

labeltestoutside.Text = "out"; //placed outside the carouselview
labeltestinside.Text = "in"; // placed inside

and put breakpoints on them, the first one will be a Xamarin.Forms.Label, but the second will still be null and make he app crash.

[AndreiMisiukevich]

Hi, and thank you for the interest in this project.

Does it work fine with Xamarin.Forms CarouselView?
I am pretty sure this bug is not related to this project.
That's more like your app's issue.

I can propose you to add views from the code behind

[grounch]

Found same behavior with the original CarouselView, so yes it's not a bug of your project.

That's what i ended up doing, created different views with my elements instead of putting everything directly in the XAML of the CarouselView, then stored the views in an ObservableCollection & setting this collection as carousel.ItemsSource in code behind.
That way the reactui bindings are in each view's code behind and accessing the elements well.