最近精简代码，有些bug，修复

AIStudio.Wpf.DiagramDesigner/UserControls/GridControl.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Controls;
+using System.Windows.Input;
+
+namespace AIStudio.Wpf.DiagramDesigner
+{
+    public class GridControl : Grid
+    {
+        public IDiagramViewModel DiagramViewModel
+        {
+            get
+            {
+                return (this.DataContext as SelectableDesignerItemViewModelBase)?.Root;
+            }
+        }
+
+        //protected override void OnPreviewKeyDown(KeyEventArgs e)
+        //{
+        //    base.OnPreviewKeyDown(e);
+
+        //    e.Handled = DiagramViewModel?.ExecuteShortcut(e) ?? false;
+        //}
+    }
+}