entrance-testing/EntranseTesting/Views/TestingViews/TestEnd.axaml

<UserControl 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"
             x:Class="EntranseTesting.TestEnd"
             x:DataType="vm:MainWindowViewModel"
             xmlns:vm="using:EntranseTesting.ViewModels">
  <ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
    <StackPanel Margin="20 0" Background="Transparent" Spacing="5"
                HorizontalAlignment="Center" VerticalAlignment="Center">
      
      <TextBlock Text="Предоставленное время на выполнение теста закончилось"
                 HorizontalAlignment="Center" Classes="Header"
                 Margin="0 0 0 15"/>
      
     <Button HorizontalAlignment="Right" 
             Command="{Binding EndTestCommand}" Margin="5"
             Content="Завершить тест"/>
    </StackPanel>
  </ScrollViewer>
</UserControl>