MainWindow.xaml

<?xml version="1.0" encoding="utf-8"?>
<winex:WindowEx
    x:Class="TagEditor.MainWindow"
    xmlns:winex="using:WinUIEx"
    
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:TagEditor"
    
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:files="using:TagEditor.Files" xmlns:controls="using:TagEditor.Controls"
    mc:Ignorable="d"
    Title="TagEditor">

    <Grid>

        <Grid.RowDefinitions>
            <RowDefinition Height="44"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!-- App's title bar -->
        <Border x:Name="AppTitleBar" VerticalAlignment="Stretch" >
            <StackPanel Orientation="Horizontal" Margin="15,0">
                <TextBlock x:Name="AppTittle" Text="TagEditor" VerticalAlignment="Center"/>
            </StackPanel>

        </Border>

        <!-- Editor component -->
        <Grid  Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
            <controls:Editor />
        </Grid>
        
    </Grid>
</winex:WindowEx>