BackgroundBuilder/Views/MainWindow.xaml.cs

using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using BackgroundBuilder.Models;
using BackgroundBuilder.ViewModels;

namespace BackgroundBuilder.Views
{
    public partial class MainWindow : Window
    {
        private readonly MainWindowViewModel _vm;

        public MainWindow(MainWindowViewModel vm)
        {
            InitializeComponent();

            this.Language = System.Windows.Markup.XmlLanguage.GetLanguage(System.Globalization.CultureInfo.CurrentUICulture.IetfLanguageTag);

            _vm = vm;
            DataContext = vm;

            // Point the VM’s OverlayElement to our DataGrid
            _vm.OverlayElement = MainGrid;

            // Load contatos on window load
            Loaded += async (_, __) => await _vm.LoadRawAsync();
        }
    }
}