optimized performance

src/Shared/HandyControl_Shared/Controls/Panel/CirclePanel.cs

@@ -23,7 +23,7 @@ namespace HandyControl.Controls
         public bool KeepVertical
         {
             get => (bool) GetValue(KeepVerticalProperty);
-            set => SetValue(KeepVerticalProperty, value);
+            set => SetValue(KeepVerticalProperty, ValueBoxes.BooleanBox(value));
         }
 
         public static readonly DependencyProperty OffsetAngleProperty = DependencyProperty.Register(

src/Shared/HandyControl_Shared/Controls/Panel/Grid/Col.cs

@@ -47,7 +47,7 @@ namespace HandyControl.Controls
         public bool IsFixed
         {
             get => (bool) GetValue(IsFixedProperty);
-            set => SetValue(IsFixedProperty, value);
+            set => SetValue(IsFixedProperty, ValueBoxes.BooleanBox(value));
         }
 
         internal int GetLayoutCellCount(ColLayoutStatus status)