项目结构调整

Others/gong-wpf-dragdrop/src/Showcase/Models/NestedDropHandler.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Windows;
+using GongSolutions.Wpf.DragDrop;
+
+namespace Showcase.WPF.DragDrop.Models
+{
+    public class NestedDropHandler : IDropTarget
+    {
+        public void DragOver(IDropInfo dropInfo)
+        {
+            if (dropInfo.TargetItem?.ToString().StartsWith("Root", StringComparison.OrdinalIgnoreCase) == true)
+            {
+                dropInfo.Effects = DragDropEffects.Move;
+                dropInfo.DropTargetAdorner = DropTargetAdorners.Highlight;
+            }
+        }
+
+        public void Drop(IDropInfo dropInfo)
+        {
+            // nothing
+        }
+    }
+}