ReactiveList does not update in the GUI - reactiveui

Question

I'm trying to make good use of ReactiveList and I think I'm close.
My expectation is that only "toyota" is shown after the user presses the filter button
XAML (yes, quick n dirty, no command for the Filter)
<Window
x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow"
Height="350"
Width="525">
<StackPanel>
<ComboBox
ItemsSource="{Binding Path=CarsVM}"
DisplayMemberPath="Name" />
<Button
Click="ButtonBase_OnClick">
Filter
</Button>
</StackPanel>
</Window>
The code
using System.Windows;
using ReactiveUI;
namespace WpfApplication1
{
public partial class MainWindow
{
private readonly ViewModel _viewModel;
public MainWindow()
{
InitializeComponent();
_viewModel = new ViewModel();
DataContext = _viewModel;
}
private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
_viewModel.ChangeFilter();
}
}
}
public class CarViewModel : ReactiveObject
{
private bool _isVisible = true;
public CarViewModel(string name)
{
Name = name;
}
public bool IsVisible
{
get { return _isVisible; }
set
{
_isVisible = value;
this.RaiseAndSetIfChanged(ref _isVisible, value);
}
}
public string Name { get; set; }
}
public class ViewModel
{
private readonly ReactiveList<CarViewModel> _cars = new ReactiveList<CarViewModel>
{
new CarViewModel("bmw"),
new CarViewModel("toyota"),
new CarViewModel("opel")
};
public ViewModel()
{
_cars.ChangeTrackingEnabled = true;
CarsVM = _cars.CreateDerivedCollection(x => x, x => x.IsVisible);
}
public IReactiveDerivedList<CarViewModel> CarsVM { get; set; }
public void ChangeFilter()
{
foreach (var car in _cars)
{
car.IsVisible = car.Name.Contains("y");
}
}
}

Answer 1

Your bug is in the setter of IsVisible. By pre-assigning the value of _isVisible, RaiseAndSetIfChanged always thinks that the value has never changed. Remove _isVisible = value; and everything should work.