performance optimization

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

@@ -37,9 +37,11 @@ namespace HandyControl.Controls
 
         protected override Size MeasureOverride(Size availableSize)
         {
-            if (Children.Count == 0) return new Size(Diameter, Diameter);
+            var diameter = Diameter;
 
-            var newSize = new Size(Diameter, Diameter);
+            if (Children.Count == 0) return new Size(diameter, diameter);
+
+            var newSize = new Size(diameter, diameter);
 
             foreach (UIElement element in Children)
             {
@@ -51,6 +53,9 @@ namespace HandyControl.Controls
 
         protected override Size ArrangeOverride(Size finalSize)
         {
+            var keepVertical = KeepVertical;
+            var offsetAngle = OffsetAngle;
+
             var i = 0;
             var perDeg = 360.0 / Children.Count;
             var radius = Diameter / 2;
@@ -59,19 +64,23 @@ namespace HandyControl.Controls
             {
                 var centerX = element.DesiredSize.Width / 2.0;
                 var centerY = element.DesiredSize.Height / 2.0;
-                var angle = perDeg * i++ + OffsetAngle;
+                var angle = perDeg * i++ + offsetAngle;
+                
                 var transform = new RotateTransform
                 {
                     CenterX = centerX,
                     CenterY = centerY,
-                    Angle = KeepVertical ? 0 : angle
+                    Angle = keepVertical ? 0 : angle
                 };
                 element.RenderTransform = transform;
+                
                 var r = Math.PI * angle / 180.0;
                 var x = radius * Math.Cos(r);
                 var y = radius * Math.Sin(r);
+                
                 var rectX = x + finalSize.Width / 2 - centerX;
                 var rectY = y + finalSize.Height / 2 - centerY;
+                
                 element.Arrange(new Rect(rectX, rectY, element.DesiredSize.Width, element.DesiredSize.Height));
             }