solved #151

src/Shared/HandyControlDemo_Shared/UserControl/Main/AppNotification.xaml

@@ -3,6 +3,8 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:hc="https://handyorg.github.io/handycontrol"
              Background="White"
+             BorderThickness="1"
+             BorderBrush="{DynamicResource BorderBrush}"
              Width="320"
              Height="518">
     <hc:SimplePanel>

src/Shared/HandyControlDemo_Shared/ViewModel/Controls/NotificationDemoViewModel.cs

@@ -21,7 +21,11 @@ namespace HandyControlDemo.ViewModel
         public ShowAnimation ShowAnimation
         {
             get => _showAnimation;
+#if netle40
+            set => Set(nameof(ShowAnimation) ,ref _showAnimation, value);
+#else
             set => Set(ref _showAnimation, value);
+#endif
         }
 
         private bool _staysOpen = true;
@@ -29,7 +33,11 @@ namespace HandyControlDemo.ViewModel
         public bool StaysOpen
         {
             get => _staysOpen;
+#if netle40
+            set => Set(nameof(StaysOpen) ,ref _staysOpen, value);
+#else
             set => Set(ref _staysOpen, value);
+#endif
         }
     }
 }