SplashScreen

LehrerApp.Desktop/App.axaml.cs

@@ -1,7 +1,9 @@
 using Avalonia;
+using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Styling;
+using Avalonia.Threading;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
 using LehrerApp.Core.Services;
@@ -37,6 +39,21 @@ public class App : Application
         ApplyTheme(new AppearanceSettingsService(AppBootstrapper.ResolveAppDataPath()).Load());
 
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            // Erst den Splashscreen anzeigen und die synchrone Initialisierung in den ersten
+            // Dispatcher-Durchlauf verschieben, damit das Ladebild vorher gezeichnet wird.
+            var splash = new SplashWindow();
+            desktop.MainWindow = splash;
+            Dispatcher.UIThread.Post(
+                () => ContinueStartup(desktop, splash),
+                DispatcherPriority.Background);
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+
+    private static void ContinueStartup(
+        IClassicDesktopStyleApplicationLifetime desktop, SplashWindow splash)
     {
         // Verschlüsselte Datenbank (13.3.4): Passwort abfragen, bevor die Datenbank
         // (und damit BuildServices, das sie öffnet) angefasst wird.
@@ -48,22 +65,20 @@ public class App : Application
             promptVm.OnUnlocked = password =>
             {
                 AppBootstrapper.DbPassword = password;
-                    StartMainApp(desktop, showImmediately: true);
+                StartMainApp(desktop, splash);
                 promptWindow.Close();
             };
             desktop.MainWindow = promptWindow;
-            }
-            else
-            {
-                StartMainApp(desktop, showImmediately: false);
-            }
+            promptWindow.Show();
+            splash.Close();
+            return;
         }
 
-        base.OnFrameworkInitializationCompleted();
+        StartMainApp(desktop, splash);
     }
 
     private static void StartMainApp(
-        IClassicDesktopStyleApplicationLifetime desktop, bool showImmediately)
+        IClassicDesktopStyleApplicationLifetime desktop, Window? windowToClose = null)
     {
         _serviceProvider = AppBootstrapper.BuildServices();
         Services = _serviceProvider;
@@ -96,7 +111,8 @@ public class App : Application
         if (Services.GetService<SyncEngine>() is { } syncEngine)
             main.EnableFinalSync(syncEngine);
         desktop.MainWindow = main;
-        if (showImmediately) main.Show();
+        main.Show();
+        windowToClose?.Close();
     }
 
     /// <summary>Wechselt die Darstellung sofort, ohne Neustart (12.4) — Avalonia stylt den

LehrerApp.Desktop/Views/SplashWindow.axaml

@@ -0,0 +1,14 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="LehrerApp.Desktop.Views.SplashWindow"
+        Title="LehrerPlaner Organizer wird geladen"
+        Width="450" Height="600"
+        CanResize="False"
+        ShowInTaskbar="False"
+        WindowDecorations="None"
+        WindowStartupLocation="CenterScreen">
+  <Image Source="/Assets/SplashScreen.png"
+         Stretch="UniformToFill"
+         HorizontalAlignment="Stretch"
+         VerticalAlignment="Stretch"/>
+</Window>

LehrerApp.Desktop/Views/SplashWindow.axaml.cs

@@ -0,0 +1,8 @@
+using Avalonia.Controls;
+
+namespace LehrerApp.Desktop.Views;
+
+public partial class SplashWindow : Window
+{
+    public SplashWindow() => InitializeComponent();
+}