From 897a71aa1304cfcba9011fcdd79f56f3efa5eb52 Mon Sep 17 00:00:00 2001
From: Dong Bin <popmessiah@hotmail.com>
Date: Fri, 24 Apr 2026 18:17:40 +0800
Subject: [PATCH] feat: implement singleton pattern for PaletteDemoViewModel
 and add initialization check

---
 demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml.cs     | 10 ++++++----
 .../ViewModels/PaletteDemoViewModel.cs                 |  5 ++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml.cs b/demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml.cs
index 33b7283..f5476e1 100644
--- a/demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml.cs
+++ b/demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml.cs
@@ -12,14 +12,16 @@ public partial class PaletteDemo : UserControl
     public PaletteDemo()
     {
         InitializeComponent();
-        this.DataContext = new PaletteDemoViewModel();
+        this.DataContext = PaletteDemoViewModel.Instance.Value;
     }
 
     protected override async void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
-        PaletteDemoViewModel? vm = this.DataContext as PaletteDemoViewModel;
-        await Dispatcher.UIThread.InvokeAsync(() => { vm?.InitializeResources(); });
+        if (this.DataContext is PaletteDemoViewModel vm && !vm.IsInitialized)
+        {
+            await Dispatcher.UIThread.InvokeAsync(() => { vm?.InitializeResources(); });
+        }
     }
 
     public async Task Copy(object? o)
@@ -31,4 +33,4 @@ public partial class PaletteDemo : UserControl
             await c.SetTextAsync(o.ToString());
         }
     }
-}
\ No newline at end of file
+}
diff --git a/demo/Semi.Avalonia.Demo/ViewModels/PaletteDemoViewModel.cs b/demo/Semi.Avalonia.Demo/ViewModels/PaletteDemoViewModel.cs
index 363c608..e3aeab8 100644
--- a/demo/Semi.Avalonia.Demo/ViewModels/PaletteDemoViewModel.cs
+++ b/demo/Semi.Avalonia.Demo/ViewModels/PaletteDemoViewModel.cs
@@ -14,6 +14,8 @@ namespace Semi.Avalonia.Demo.ViewModels;
 
 public partial class PaletteDemoViewModel : ObservableObject
 {
+    public static Lazy<PaletteDemoViewModel> Instance { get; } = new(() => new PaletteDemoViewModel());
+    public bool IsInitialized { get; private set; }
     private readonly string[] _predefinedColorNames =
     [
         "Red", "Pink", "Purple", "Violet", "Indigo",
@@ -44,6 +46,7 @@ public partial class PaletteDemoViewModel : ObservableObject
         InitializePalette();
         InitializeFunctionalColors();
         InitializeShadows();
+        IsInitialized = true;
     }
 
     private void InitializePalette()
@@ -289,4 +292,4 @@ public partial class ShadowGroupViewModel : ObservableObject
             }
         }
     }
-}
\ No newline at end of file
+}