Add project files.

App.config

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+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
+    </startup>
+</configuration>

App.xaml

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+<Application x:Class="UiDesignTinkering.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:UiDesignTinkering"
+             Startup="Application_Startup">
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="Styles.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

App.xaml.cs

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+using System.Windows;
+
+namespace UiDesignTinkering
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+        private void Application_Startup(object sender, StartupEventArgs e)
+        {
+            var mainWindow = new MainWindow
+            {
+                DataContext = new MainWindowViewModel()
+            };
+            mainWindow.Show();
+        }
+    }
+}

BaseModel.cs

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+namespace UiDesignTinkering
+{
+    public abstract class BaseModel : IModel
+    {
+    }
+}

BaseViewModel.cs

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+using GalaSoft.MvvmLight;
+
+namespace UiDesignTinkering
+{
+    public abstract class BaseViewModel : ViewModelBase, IViewModel
+    {
+    }
+}

Client.cs

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+namespace UiDesignTinkering
+{
+    public class Client : BaseModel
+    {
+    }
+}

ClientView.xaml

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+<UserControl x:Class="UiDesignTinkering.ClientView"
+             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:UiDesignTinkering"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <TextBlock>Client</TextBlock>
+    </Grid>
+</UserControl>

ClientView.xaml.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace UiDesignTinkering
+{
+    /// <summary>
+    /// Interaction logic for ClientView.xaml
+    /// </summary>
+    public partial class ClientView : UserControl
+    {
+        public ClientView()
+        {
+            InitializeComponent();
+        }
+    }
+}

IMainViewModel.cs

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+namespace UiDesignTinkering
+{
+    public interface IMainViewModel : IViewModel
+    {
+        bool HasFocus { get; set; }
+    }
+}

IModel.cs

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+namespace UiDesignTinkering
+{
+    public interface IModel
+    {
+    }
+}

IViewModel.cs

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+namespace UiDesignTinkering
+{
+    public interface IViewModel
+    {
+
+    }
+}

InsuranceStore.cs

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+namespace UiDesignTinkering
+{
+    public class InsuranceStore : Store
+    {
+    }
+}

InsuranceView.xaml

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+<UserControl x:Class="UiDesignTinkering.InsuranceView"
+             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:UiDesignTinkering"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <TextBlock>Insurance</TextBlock>
+    </Grid>
+</UserControl>

InsuranceView.xaml.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace UiDesignTinkering
+{
+    /// <summary>
+    /// Interaction logic for InsuranceView.xaml
+    /// </summary>
+    public partial class InsuranceView : UserControl
+    {
+        public InsuranceView()
+        {
+            InitializeComponent();
+        }
+    }
+}

InverseBoolToVisibilityConverter.cs

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+using System;
+using System.Globalization;
+using System.Windows.Controls;
+using System.Windows.Data;
+
+namespace UiDesignTinkering
+{
+    class InverseBoolToVisibilityConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return new BooleanToVisibilityConverter().Convert(value, targetType, parameter, culture);
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return new BooleanToVisibilityConverter().ConvertBack(value, targetType, parameter, culture);
+        }
+    }
+}

MainViewModel.cs

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+using GalaSoft.MvvmLight;
+
+namespace UiDesignTinkering
+{
+    public class MainViewModel<T> : BaseViewModel, IMainViewModel
+        where T : IModel
+    {
+        private bool _hasFocus;
+
+        public bool HasFocus
+        {
+            get => _hasFocus;
+            set => Set(ref _hasFocus, value);
+        }
+    }
+}

MainViews.cs

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+namespace UiDesignTinkering
+{
+    public enum MainViews
+    {
+        ServiceCharge,
+        Insurance,
+        Rent,
+        Scheme,
+        Client,
+        News,
+        Task
+    }
+}

MainWindow.xaml

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+<Window x:Class="UiDesignTinkering.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:UiDesignTinkering"
+        mc:Ignorable="d"
+        Title="MainWindow" Height="450" Width="800">
+    <Window.Resources>
+        <local:RadioButtonCheckedConverter x:Key="RadioButtonConverter"/>
+        <BooleanToVisibilityConverter x:Key="BoolToVisibilityConverter"/>
+    </Window.Resources>
+    <Grid Margin="10">
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="100"/>
+            <ColumnDefinition/>
+        </Grid.ColumnDefinitions>
+        <StackPanel Grid.Column="0">
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.ServiceCharge}}">
+                Service Charge
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.Insurance}}">
+                Insurance
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.Rent}}">
+                Rent
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.Scheme}}">
+                Scheme
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.Client}}">
+                Client
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.News}}">
+                News
+            </RadioButton>
+            <RadioButton GroupName="MainViews" 
+                         IsChecked="{Binding MainViewSelected, Converter={StaticResource RadioButtonConverter}, ConverterParameter={x:Static local:MainViews.Task}}">
+                Task
+            </RadioButton>
+        </StackPanel>
+        <Grid Grid.Column="1" Margin="5">
+            <StackPanel Visibility="{Binding ServiceChargeStoreViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:ServiceChargeView DataContext="{Binding ServiceChargeStoreViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding InsuranceStoreViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:InsuranceView DataContext="{Binding InsuranceStoreViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding RentStoreViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:RentView DataContext="{Binding RentStoreViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding SchemeViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:SchemeView DataContext="{Binding SchemeViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding ClientViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:ClientView DataContext="{Binding ClientViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding NewsViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:NewsView DataContext="{Binding NewsViewModel}"/>
+            </StackPanel>
+            <StackPanel Visibility="{Binding TaskViewModel.HasFocus, Converter={StaticResource BoolToVisibilityConverter}}">
+                <local:TaskView DataContext="{Binding TaskViewModel}"/>
+            </StackPanel>
+        </Grid>
+    </Grid>
+</Window>

MainWindow.xaml.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace UiDesignTinkering
+{
+    public partial class MainWindow : Window
+    {
+        public MainWindow()
+        {
+            InitializeComponent();
+        }
+
+
+    }
+}

MainWindowViewModel.cs

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+using GalaSoft.MvvmLight;
+using System.Collections.Generic;
+
+namespace UiDesignTinkering
+{
+    public class MainWindowViewModel : ViewModelBase
+    {
+        private MainViews _mainViewSelected;
+        private readonly IDictionary<int, IMainViewModel> _mainViewModels;
+
+        public MainWindowViewModel()
+        {
+            ServiceChargeStoreViewModel = new MainViewModel<ServiceChargeStore>();
+            InsuranceStoreViewModel = new MainViewModel<InsuranceStore>();
+            RentStoreViewModel = new MainViewModel<RentStore>();
+            SchemeViewModel = new MainViewModel<Scheme>();
+            ClientViewModel = new MainViewModel<Client>();
+            NewsViewModel = new MainViewModel<News>();
+            TaskViewModel = new MainViewModel<Task>();
+            _mainViewModels = new Dictionary<int, IMainViewModel>
+            {
+                { (int)MainViews.ServiceCharge, ServiceChargeStoreViewModel },
+                { (int)MainViews.Insurance, InsuranceStoreViewModel },
+                { (int)MainViews.Rent, RentStoreViewModel },
+                { (int)MainViews.Scheme, SchemeViewModel },
+                { (int)MainViews.Client, ClientViewModel },
+                { (int)MainViews.News, NewsViewModel },
+                { (int)MainViews.Task, TaskViewModel }
+            };
+            MainViewSelected = MainViews.News;
+        }
+
+        public MainViews MainViewSelected
+        {
+            get => _mainViewSelected;
+            set
+            {
+                Set(ref _mainViewSelected, value);
+                SetFocusOnMainViewModels();
+            }
+        }
+
+        public IMainViewModel ServiceChargeStoreViewModel { get; }
+
+        public IMainViewModel InsuranceStoreViewModel { get; }
+
+        public IMainViewModel RentStoreViewModel { get; }
+
+        public IMainViewModel SchemeViewModel { get; }
+
+        public IMainViewModel ClientViewModel { get; }
+
+        public IMainViewModel NewsViewModel { get; }
+
+        public IMainViewModel TaskViewModel { get; }
+
+        private void SetFocusOnMainViewModels()
+        {
+            foreach (var key in _mainViewModels.Keys)
+            {
+                var isSelected = key == (int)MainViewSelected; 
+                _mainViewModels[key].HasFocus = isSelected;
+            }
+        }
+    }
+}