diff --git a/DeedyDesigner/Deedy.Activity/Adorner/DragPlacementAdorner.cs b/DeedyDesigner/Deedy.Activity/Adorner/DragPlacementAdorner.cs
index f187f2d..055135b 100644
--- a/DeedyDesigner/Deedy.Activity/Adorner/DragPlacementAdorner.cs
+++ b/DeedyDesigner/Deedy.Activity/Adorner/DragPlacementAdorner.cs
@@ -35,6 +35,6 @@ namespace Deedy.Activity
         }
 
         protected override void OnRender(DrawingContext drawingContext)
-            => this.Help_DrawDropAdorner(drawingContext, this.DropPlacement, this.LayoutDirection, _Pen, _Brush);
+            => drawingContext.Help_DrawDropAdorner(this.AdornedElement.RenderSize, this.DropPlacement, this.LayoutDirection, _Pen, _Brush);
     }
 }
diff --git a/DeedyDesigner/Deedy.Activity/Helpers/VisualHelper.cs b/DeedyDesigner/Deedy.Activity/Helpers/VisualHelper.cs
index 0096dfa..6bd5444 100644
--- a/DeedyDesigner/Deedy.Activity/Helpers/VisualHelper.cs
+++ b/DeedyDesigner/Deedy.Activity/Helpers/VisualHelper.cs
@@ -20,18 +20,16 @@ namespace Deedy.Activity
         /// <summary>
         /// 辅助可视化单元进行拖放装饰器绘制操作
         /// </summary>
-        /// <param name="ui">要绘制的「UIElement」元素</param>
         /// <param name="dc">「UIElement」元素的绘图上下文</param>
         /// <param name="dropPlacement">拖放操作的放置位置</param>
         /// <param name="parentLayoutDirection">父级布局的布局方向</param>
-        public static void Help_DrawDropAdorner(this UIElement ui, DrawingContext dc,
+        public static void Help_DrawDropAdorner(this DrawingContext dc,Size size,
             DropPlacement dropPlacement, LayoutDirection? parentLayoutDirection,
             Pen? _Pen = null, Brush? _Brush = null)
         {
-            if (ui == null || dc == null || dropPlacement == DropPlacement.UnDragged) return;
+            if (dc == null || dropPlacement == DropPlacement.UnDragged) return;
             Pen pen = _Pen ?? new Pen(Brushes.Transparent, 0);
             Brush brush = _Brush ?? new SolidColorBrush(Colors.Red) { Opacity = 0.5 };
-            Size size = ui.RenderSize;
             ThemeResources res = new();
 
             switch (dropPlacement)