MainView.xaml

<UserControl xmlns="https://github.com/avaloniaui"
        xmlns:pages="clr-namespace:ControlCatalog.Pages"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="ControlCatalog.MainView">
  <Grid>
    <Grid.Styles>
        <Style Selector="TextBlock.h2">
            <Setter Property="TextWrapping" Value="Wrap"/>
            <Setter Property="MaxWidth" Value="400"/>
            <Setter Property="HorizontalAlignment" Value="Left"/>
        </Style>
    </Grid.Styles>  
    <TabControl Classes="sidebar" Name="Sidebar">
      <TabItem Header="Acrylic"><pages:AcrylicPage/></TabItem>
      <TabItem Header="AutoCompleteBox"><pages:AutoCompleteBoxPage/></TabItem>
      <TabItem Header="Border"><pages:BorderPage/></TabItem>
      <TabItem Header="Button"><pages:ButtonPage/></TabItem>
      <TabItem Header="ButtonSpinner"><pages:ButtonSpinnerPage/></TabItem>
      <TabItem Header="Calendar"><pages:CalendarPage/></TabItem>
      <TabItem Header="Canvas"><pages:CanvasPage/></TabItem>
      <TabItem Header="Carousel"><pages:CarouselPage/></TabItem>
      <TabItem Header="CheckBox"><pages:CheckBoxPage/></TabItem>
      <TabItem Header="ComboBox"><pages:ComboBoxPage/></TabItem>
      <TabItem Header="ContextMenu"><pages:ContextMenuPage/></TabItem>
      <TabItem Header="DataGrid" 
               ScrollViewer.VerticalScrollBarVisibility="Disabled"
               ScrollViewer.HorizontalScrollBarVisibility="Disabled">
          <pages:DataGridPage/>
      </TabItem>
      <TabItem Header="Date/Time Picker">
        <pages:DateTimePickerPage/>
      </TabItem>
      <TabItem Header="CalendarDatePicker">
        <pages:CalendarDatePickerPage/></TabItem>
      <TabItem Header="Drag+Drop"><pages:DragAndDropPage/></TabItem>
      <TabItem Header="Expander"><pages:ExpanderPage/></TabItem>
      <TabItem Header="Image"
               ScrollViewer.VerticalScrollBarVisibility="Disabled"
               ScrollViewer.HorizontalScrollBarVisibility="Disabled">
        <pages:ImagePage/>
      </TabItem>
      <TabItem Header="ItemsRepeater"
               ScrollViewer.VerticalScrollBarVisibility="Disabled"
               ScrollViewer.HorizontalScrollBarVisibility="Disabled">
        <pages:ItemsRepeaterPage/>
      </TabItem>
      <TabItem Header="Label"><pages:LabelsPage/></TabItem>
      <TabItem Header="LayoutTransformControl"><pages:LayoutTransformControlPage/></TabItem>
      <TabItem Header="ListBox"
               ScrollViewer.VerticalScrollBarVisibility="Disabled">
        <pages:ListBoxPage/>
      </TabItem>
      <TabItem Header="Menu"><pages:MenuPage/></TabItem>
      <TabItem Header="Notifications"><pages:NotificationsPage/></TabItem>
	    <TabItem Header="NumericUpDown"><pages:NumericUpDownPage/></TabItem>
      <TabItem Header="OpenGL"><pages:OpenGlPage/></TabItem>
      <TabItem Header="Pointers (Touch)"><pages:PointersPage/></TabItem>
      <TabItem Header="ProgressBar"><pages:ProgressBarPage/></TabItem>
      <TabItem Header="RadioButton"><pages:RadioButtonPage/></TabItem>
      <TabItem Header="RelativePanel"><pages:RelativePanelPage/></TabItem>
      <TabItem Header="ScrollViewer"><pages:ScrollViewerPage/></TabItem>
      <TabItem Header="Slider"><pages:SliderPage/></TabItem>
      <TabItem Header="SplitView"><pages:SplitViewPage/></TabItem>
      <TabItem Header="TabControl"><pages:TabControlPage/></TabItem>
      <TabItem Header="TabStrip"><pages:TabStripPage/></TabItem>
      <TabItem Header="TextBox"><pages:TextBoxPage/></TabItem>
      <TabItem Header="TextBlock"><pages:TextBlockPage/></TabItem>
      <TabItem Header="ToggleSwitch"><pages:ToggleSwitchPage/></TabItem>
      <TabItem Header="ToolTip"><pages:ToolTipPage/></TabItem>
      <TabItem Header="TreeView"><pages:TreeViewPage/></TabItem>
      <TabItem Header="Viewbox"><pages:ViewboxPage/></TabItem>
      <TabItem Header="Window Customizations"><pages:WindowCustomizationsPage/></TabItem>
      <TabControl.Tag>
        <StackPanel Width="115" Spacing="4" HorizontalAlignment="Right" VerticalAlignment="Bottom" Margin="8">
          <ComboBox x:Name="Decorations" SelectedIndex="0">
            <ComboBoxItem>No Decorations</ComboBoxItem>
            <ComboBoxItem>Border Only</ComboBoxItem>
            <ComboBoxItem>Full Decorations</ComboBoxItem>
          </ComboBox>
          <ComboBox x:Name="Themes" SelectedIndex="0">
            <ComboBoxItem>Fluent - Light</ComboBoxItem>
            <ComboBoxItem>Fluent - Dark</ComboBoxItem>
            <ComboBoxItem>Simple - Light</ComboBoxItem>
            <ComboBoxItem>Simple - Dark</ComboBoxItem>
          </ComboBox>
          <ComboBox x:Name="TransparencyLevels" SelectedIndex="{Binding TransparencyLevel}">
            <ComboBoxItem>None</ComboBoxItem>
            <ComboBoxItem>Transparent</ComboBoxItem>
            <ComboBoxItem>Blur</ComboBoxItem>
            <ComboBoxItem>AcrylicBlur</ComboBoxItem>
          </ComboBox>
          <ComboBox Items="{Binding WindowStates}" SelectedItem="{Binding WindowState}" />
        </StackPanel>
      </TabControl.Tag>
    </TabControl>
  </Grid>
</UserControl>