Reactive UI Getting started with compelling example wont work

Question

I did this many times, but now it just doest work.

I am following this example: https://www.reactiveui.net/docs/handbook/routing/

I have my MainWindow.xaml.cs

using ReactiveUI;

namespace KardexTerminal_WPF
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : ReactiveWindow<MainViewModel>
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }
}

MainWindow.xaml

<rxui:ReactiveWindow x:Class="KardexTerminal_WPF.MainWindow"
         xmlns:rxui="https://reactiveui.net" 
        x:TypeArguments="local:MainViewModel"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:KardexTerminal_WPF"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>

    </Grid>
</rxui:ReactiveWindow>

MainViewModel:

using ReactiveUI;

namespace KardexTerminal_WPF
{
    public class MainViewModel : ReactiveObject, IScreen
    {
        public MainViewModel()
        {
            Router = new RoutingState();
        }

        public RoutingState Router { get; }
    }
}

Simple as documentation suggest. This is completely new project and have only ReactiveUI and ReactiveUI.WPF packages installed.

But I am getting those error:

I will be glad for any help, if anyone knows what is the issue.

EDIT 1: If I implement IViewFor, then it works.

I have tried suggestions from comments on view usercontrol:

<rxui:ReactiveUserControl x:Class="KardexTerminal_WPF.Views.LoginView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:KardexTerminal_WPF.Views"
             mc:Ignorable="d" 
             xmlns:vm="clr-namespace:KardexTerminal.ViewModels;assembly=KardexTerminal"
             x:TypeArguments="vm:LoginViewModel"
             xmlns:rxui="https://reactiveui.net"
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>
            
    </Grid>
</rxui:ReactiveUserControl>

namespace KardexTerminal_WPF.Views
{
    /// <summary>
    /// Interaction logic for LoginView.xaml
    /// </summary>
    public partial class LoginView
    {
        public LoginView()
        {
            InitializeComponent();
        }
    }
}

But that makes those errors, I am not sure what is wrong:

I am using those packages:

EDIT 2: Answer below from @mm8 helped to make the program compile. ReactiveUI has wrong documentation and should be fixed: https://www.reactiveui.net/docs/handbook/routing/

But there is stil error, which I cannot seem to get rid off. I will proceed with that at GitHub issue.

Answer 1

The namespace is http://reactiveui.net (and not https://...):

xmlns:rxui="http://reactiveui.net"

Besides this, your code-behind class should inherit from ReactiveUserControl<LoginViewModel> since this is the base class you have specified in the XAML markup:

public partial class LoginView : ReactiveUserControl<LoginViewModel>
{
    public LoginView()
    {
        InitializeComponent();
    }
}

Answer 2

I've got similar problems using the ReactiveUserControl class. I've found 2 workaround for this

1)Create a base class for your window that inherit from ReactiveWindow than let MainWindow inherit from that class

 public class MainWindowBase : ReactiveWindow<MainViewModel> { }

 /// <summary>
 /// Interaction logic for MainWindow.xaml
 /// </summary>
 public partial class MainWindow 
 { 
        public MainWindow()
        {
            InitializeComponent();
        }
}

Than in your xaml

<local:MainWindowBase x:Class="YourNameSpace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:YourNameSpace"
        mc:Ignorable="d"
        Title="" Height="600" Width="1000" >

2)Implement manually the IViewFor<T>

public partial class MainWindow : Window, IViewFor<MainViewModel>
    {
        public static readonly DependencyProperty ViewModelProperty = DependencyProperty.Register("ViewModel", typeof(MainViewModel), typeof(MainWindow));

        public MainViewModel ViewModel
        {
            get { return (MainViewModel)GetValue(ViewModelProperty); }
            set { SetValue(ViewModelProperty, value); }
        }

        object IViewFor.ViewModel
        {
            get => ViewModel;
            set => ViewModel = (MainViewModel)value;
        }


        public MainWindow()
        {
            InitializeComponent();
        }
       }

EDIT: based on the comment of Glenn Watson I've updated the answer but for completeness I'll add here the previous answer that will be usefull when working on the UWP

public class MainWindowBase : ReactiveWindow<MainViewModel> { }

 /// <summary>
 /// Interaction logic for MainWindow.xaml
 /// </summary>
 public partial class MainWindow :MainWindowBase 
 { 
        public MainWindow()
        {
            InitializeComponent();
        }
}