Avalonia/samples/ControlCatalog/Pages/ButtonPage.paml

<UserControl xmlns="https://github.com/perspex">
  <StackPanel Orientation="Vertical" Gap="4">
    <TextBlock Classes="h1">Button</TextBlock>
    <TextBlock Classes="h2">A button control</TextBlock>

    <StackPanel Orientation="Horizontal"
                Margin="0,16,0,0"
                HorizontalAlignment="Center"
                Gap="16">
      <StackPanel Orientation="Vertical" Gap="8" Width="150">
        <Button>Button</Button>
        <Button Foreground="Blue">Foreground</Button>
        <Button Background="#f44336">Background</Button>
        <Button IsEnabled="False">Disabled</Button>
      </StackPanel>

      <StackPanel Orientation="Vertical" Gap="8" Width="150">
        <Button BorderThickness="0">No Border</Button>
        <Button BorderBrush="#f44336">Border Color</Button>
        <Button BorderBrush="#f44336" BorderThickness="4">Thick Border</Button>
        <Button BorderBrush="#f44336" BorderThickness="4" IsEnabled="False">Disabled</Button>
      </StackPanel>
    </StackPanel>
    
  </StackPanel>
</UserControl>