📄 src/App/Views/MainView.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"
             xmlns:vm="using:MMirror.App.ViewModels"
             mc:Ignorable="d" d:DesignWidth="720" d:DesignHeight="1280"
             x:Class="MMirror.App.Views.MainView"
             x:DataType="vm:MainViewModel">
    <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:MainViewModel />
    </Design.DataContext>

    <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="8">
        <TextBlock Text="{Binding Greeting}"/>
        <Rectangle Width="32" Height="32" Fill="#bada55" />
    </StackPanel>
</UserControl>