avaloniaProjForMe/kuzminIVProjectWorkOnDemo/Views/MainWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:kuzminIVProjectWorkOnDemo.ViewModels"
        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="kuzminIVProjectWorkOnDemo.Views.MainWindow"
        x:DataType="vm:MainWindowViewModel"
        Icon="/Assets/school_logo.ico"
        Title="Школа языков Леарн">

    <Design.DataContext>
        <!-- This only sets the DataContext for the previewer in an IDE,
             to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
        <vm:MainWindowViewModel/>
    </Design.DataContext>

	<Grid>
		<Grid.RowDefinitions>
			<RowDefinition Height="100"/>
			<RowDefinition Height="*"/>
		</Grid.RowDefinitions>
		<StackPanel Grid.Row="0" Margin="10">
			<Image Source="/Assets/school_logo.png" Width="50" />
			<TextBlock Text="Школа языков Леарн " Classes ="Header"/>
			
		</StackPanel>
		<StackPanel HorizontalAlignment="Right" Margin="10">
			<TextBlock Text="Режим администратора" Classes ="Default" />
			<TextBox Text="{Binding Adminkey}" />
		</StackPanel>

		<ContentControl Grid.Row="1" Content="{Binding UserControl}" />
		
	</Grid>
</Window>