Avalonia/samples/ControlCatalog/Pages/SettingsPage.axaml

<ContentPage Theme="{StaticResource ScrollPage}" xmlns="https://github.com/avaloniaui"
             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"
             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
             xmlns:local="using:ControlCatalog"
             xmlns:models="using:ControlCatalog.Models"
             Header="Settings"
             Margin="20"
             xmlns:viewModels="using:ControlCatalog.ViewModels"
             x:DataType="viewModels:SettingsViewModel"
             x:Class="ControlCatalog.Pages.SettingsPage">
  <ContentPage.Resources>
    <ResourceDictionary>
      <ResourceDictionary.ThemeDictionaries>
        <ResourceDictionary x:Key="Default">
          <SolidColorBrush x:Key="CardBackground" Color="#FFFFFF" />
          <SolidColorBrush x:Key="CardBorderBrush" Color="#E5E5EA" />
          <SolidColorBrush x:Key="CardBorderBrushHover" Color="#3E6DF3" />
          <SolidColorBrush x:Key="SubtleForeground" Color="#64646E" />
          <SolidColorBrush x:Key="BadgeBackground" Color="#E8EFFD" />
          <SolidColorBrush x:Key="BadgeForeground" Color="#3462D9" />
        </ResourceDictionary>
        <ResourceDictionary x:Key="Dark">
          <SolidColorBrush x:Key="CardBackground" Color="#2B2B33" />
          <SolidColorBrush x:Key="CardBorderBrush" Color="#3A3A45" />
          <SolidColorBrush x:Key="CardBorderBrushHover" Color="#8AB4FF" />
          <SolidColorBrush x:Key="SubtleForeground" Color="#9C9CAB" />
          <SolidColorBrush x:Key="BadgeBackground" Color="#31395A" />
          <SolidColorBrush x:Key="BadgeForeground" Color="#8AB4FF" />
        </ResourceDictionary>
      </ResourceDictionary.ThemeDictionaries>
    </ResourceDictionary>
  </ContentPage.Resources>
  <ContentPage.Styles>
    <Style Selector="ComboBox">
      <Setter Property="MinWidth">200</Setter>
    </Style>
    <Style Selector="Border.card">
      <Setter Property="Background" Value="{DynamicResource CardBackground}"/>
      <Setter Property="BorderBrush" Value="{DynamicResource CardBorderBrush}" />
      <Setter Property="BorderThickness" Value="1"/>
      <Setter Property="Padding" Value="10"/>
      <Setter Property="CornerRadius" Value="10"/>
    </Style>
    <Style Selector="Border.card Label">
      <Setter Property="VerticalAlignment" Value="Center"/>
    </Style>
  </ContentPage.Styles>
  <StackPanel Orientation="Vertical" Spacing="10">
    <Border Classes="card">

      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Window Decorations</Label>
        <ComboBox x:Name="Decorations"
                  Grid.Column="1"
                  HorizontalAlignment="Stretch"
                  SelectedIndex="{Binding SelectedDecorationIndex}"
                  SelectionChanged="Decorations_SelectionChanged"
                  ToolTip.Tip="System Decorations">
          <ComboBox.Items>
            <WindowDecorations>None</WindowDecorations>
            <WindowDecorations>BorderOnly</WindowDecorations>
            <WindowDecorations>Full</WindowDecorations>
          </ComboBox.Items>
        </ComboBox>
      </Grid>
    </Border>

    <Border Classes="card">
      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Theme</Label>
        <ComboBox HorizontalAlignment="Stretch"
                  Grid.Column="1"
                  SelectedItem="{x:Static local:App.CurrentTheme}"
                  SelectionChanged="Themes_SelectionChanged"
                  ToolTip.Tip="Catalog Theme">
          <ComboBox.Items>
            <models:CatalogTheme>Fluent</models:CatalogTheme>
            <models:CatalogTheme>Simple</models:CatalogTheme>
          </ComboBox.Items>
        </ComboBox>
      </Grid>
    </Border>

    <Border Classes="card">
      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Theme Variant</Label>
        <ComboBox HorizontalAlignment="Stretch"
                  Grid.Column="1"
                  DisplayMemberBinding="{Binding Key, x:DataType=ThemeVariant}"
                  SelectedIndex="{Binding SelectedThemeVariantIndex}"
                  SelectionChanged="ThemeVariants_SelectionChanged"
                  ToolTip.Tip="Theme Variant">
          <ComboBox.Items>
            <ThemeVariant>Default</ThemeVariant>
            <ThemeVariant>Light</ThemeVariant>
            <ThemeVariant>Dark</ThemeVariant>
          </ComboBox.Items>
        </ComboBox>
      </Grid>
    </Border>

    <Border Classes="card">
      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Window Transparency</Label>
        <ComboBox HorizontalAlignment="Stretch"
                  Grid.Column="1"
                  SelectedIndex="{Binding SelectedTransparencyLevelIndex}"
                  SelectionChanged="TransparencyLevels_SelectionChanged"
                  ToolTip.Tip="Window Transparency Level">
          <ComboBox.Items>
            <WindowTransparencyLevel>None</WindowTransparencyLevel>
            <WindowTransparencyLevel>Transparent</WindowTransparencyLevel>
            <WindowTransparencyLevel>Blur</WindowTransparencyLevel>
            <WindowTransparencyLevel>AcrylicBlur</WindowTransparencyLevel>
            <WindowTransparencyLevel>Mica</WindowTransparencyLevel>
          </ComboBox.Items>
        </ComboBox>
      </Grid>
    </Border>

    <Border Classes="card">
      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Flow Direction</Label>
        <ComboBox HorizontalAlignment="Stretch"
                  Grid.Column="1"
                  SelectedIndex="{Binding SelectedFlowDirectionIndex}"
                  SelectionChanged="FlowDirection_SelectionChanged"
                  ToolTip.Tip="Flow Direction">
          <ComboBox.Items>
            <FlowDirection>LeftToRight</FlowDirection>
            <FlowDirection>RightToLeft</FlowDirection>
          </ComboBox.Items>
        </ComboBox>
      </Grid>
    </Border>

    <Border Classes="card">
      <Grid ColumnSpacing="10" ColumnDefinitions="*,Auto">
        <Label>Window State</Label>          
        <ComboBox HorizontalAlignment="Stretch"
                  Grid.Column="1"
                  ItemsSource="{Binding WindowStates}"
                  SelectedItem="{Binding WindowState}"
                  ToolTip.Tip="Window State"/>
      </Grid>
    </Border>
  </StackPanel>
</ContentPage>