bo/Workbench/QMonitor/qmonlib.ui/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="clr-namespace:qmonlib.ui.ViewModels"
             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
             x:Class="qmonlib.ui.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>

  <TextBlock Text="{Binding Greeting}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
</UserControl>