XAML — окно WPF

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Demo" Height="220" Width="360">
  <StackPanel Margin="16">
    <TextBlock x:Name="Status" Text="Готово" />
    <Button Content="Нажми" Margin="0,12,0,0" Click="OnClick" />
  </StackPanel>
</Window>

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Demo" Height="220" Width="360">
  <StackPanel Margin="16">
    <TextBlock x:Name="Status" Text="Готово" />
    <Button Content="Нажми" Margin="0,12,0,0" Click="OnClick" />
  </StackPanel>
</Window>