fix:issue #339

Ink Canvas/MainWindow_cs/MW_FloatingBarIcons.cs

@@ -709,7 +709,49 @@ namespace Ink_Canvas
                     BlackBoardWaterMark.Visibility = Visibility.Collapsed;
                 }
 
-                _ = UpdateChickenSoupTextAsync();
+                try
+                {
+                    _ = UpdateChickenSoupTextAsync();
+                }
+                catch (Exception ex)
+                {
+                    try
+                    {
+                        LogHelper.WriteLogToFile($"进入白板模式时更新名言失败: {ex.Message}", LogHelper.LogType.Warning);
+                    }
+                    catch
+                    {
+                    }
+                    if (Settings.Appearance.EnableChickenSoupInWhiteboardMode && Settings.Appearance.ChickenSoupSource != 3)
+                    {
+                        try
+                        {
+                            if (Settings.Appearance.ChickenSoupSource == 0)
+                            {
+                                int randChickenSoupIndex = new Random().Next(ChickenSoup.OSUPlayerYuLu.Length);
+                                BlackBoardWaterMark.Text = ChickenSoup.OSUPlayerYuLu[randChickenSoupIndex];
+                            }
+                            else if (Settings.Appearance.ChickenSoupSource == 1)
+                            {
+                                int randChickenSoupIndex = new Random().Next(ChickenSoup.MingYanJingJu.Length);
+                                BlackBoardWaterMark.Text = ChickenSoup.MingYanJingJu[randChickenSoupIndex];
+                            }
+                            else if (Settings.Appearance.ChickenSoupSource == 2)
+                            {
+                                int randChickenSoupIndex = new Random().Next(ChickenSoup.GaoKaoPhrases.Length);
+                                BlackBoardWaterMark.Text = ChickenSoup.GaoKaoPhrases[randChickenSoupIndex];
+                            }
+                        }
+                        catch
+                        {
+                            BlackBoardWaterMark.Visibility = Visibility.Collapsed;
+                        }
+                    }
+                    else if (Settings.Appearance.EnableChickenSoupInWhiteboardMode && Settings.Appearance.ChickenSoupSource == 3)
+                    {
+                        BlackBoardWaterMark.Text = "一言功能不可用";
+                    }
+                }
 
                 if (Settings.Canvas.UsingWhiteboard)
                 {

Ink Canvas/MainWindow_cs/MW_Settings.cs

@@ -360,7 +360,18 @@ namespace Ink_Canvas
 
                     try
                     {
-                        var clientObj = HitokotoHttpClient.Value;
+                        object clientObj = null;
+                        try
+                        {
+                            clientObj = HitokotoHttpClient.Value;
+                        }
+                        catch (Exception initEx)
+                        {
+                            LogHelper.WriteLogToFile($"HTTP 客户端初始化失败: {initEx.Message}", LogHelper.LogType.Warning);
+                            BlackBoardWaterMark.Text = "一言功能不可用（缺少 System.Net.Http）";
+                            return;
+                        }
+
                         if (clientObj == null || !(clientObj is HttpClient client))
                         {
                             BlackBoardWaterMark.Text = "一言功能不可用（缺少 System.Net.Http）";