MVVM Implementing started

SewerStammGen/App.xaml.cs

@@ -1,4 +1,8 @@
-using System;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using SewerStammGen.HostBuilders;
+using SewerStammGen.ViewModel;
+using System;
 using System.Collections.Generic;
 using System.Configuration;
 using System.Data;
@@ -13,5 +17,52 @@ namespace SewerStammGen
     /// </summary>
     public partial class App : Application
     {
+        private readonly IHost _host;
+        public App()
+        {
+            _host = CreateHostBuilder().Build();
+        }
+
+        static IHostBuilder CreateHostBuilder(string[]? args = null)
+        {
+            return Host.CreateDefaultBuilder(args)
+                .AddConfiguration()
+                .AddServices()
+                .AddViewModels()
+                .AddStores()
+                .AddDBContext();
+        }
+
+        protected override void OnStartup(StartupEventArgs e)
+        {
+            Application.Current.DispatcherUnhandledException += Current_DispatcherUnhandledException;
+            AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
+
+            _host.Start();
+
+            MainWindow? window = new MainWindow() { DataContext = _host.Services.GetRequiredService<MainWindowViewModel>() };
+            window.Show();
+
+            base.OnStartup(e);
+        }
+
+        private void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
+        {
+            try
+            {
+                Exception ex = (Exception)e.ExceptionObject;
+                string text = "An application error occured. Plrease contact the Administrator with the following information:\n\n";
+                MessageBox.Show(text + " " + ex.Message + "\n\n" + ex.StackTrace);
+            }
+            catch (Exception ex2)
+            {
+                MessageBox.Show("Fatal Non-UI error", ex2.Message, MessageBoxButton.OK, MessageBoxImage.Error);
+            }
+        }
+
+        private void Current_DispatcherUnhandledException(object sender, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e)
+        {
+            throw new NotImplementedException();
+        }
     }
 }