连接点可以添加文字

AIStudio.Wpf.DiagramDesigner/ViewModels/ISelectable.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Linq;
 using System.Text;
 
@@ -7,6 +8,18 @@ namespace AIStudio.Wpf.DiagramDesigner
 {
     public interface ISelectable
     {
-        bool IsSelected { get; set; }
+        bool IsSelected
+        {
+            get; set;
+        }
+
+        bool IsHitTestVisible
+        {
+            get;
+        }
+
+        void AddToSelection(bool selected);
+
+        event PropertyChangedEventHandler PropertyChanged;
     }
 }