连线优化1：开始和结束节点。

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/ConnectorPointModel.cs

@@ -73,7 +73,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                 ConnectorWidth = designer.ConnectorWidth;
                 ConnectorHeight = designer.ConnectorHeight;
             }
-        }
+        }      
 
         /// <summary>
         /// 中间X

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/ConnectorVertexModel.cs

@@ -51,6 +51,11 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         }
 
+        public ConnectorVertexType ConnectorVertexType
+        {
+            get; set;
+        }
+
         public ConnectionViewModel Connector
         {
             get
@@ -82,5 +87,18 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        public void SetPosition(PointBase position)
+        {
+            X = position.X;
+            Y = position.Y;
+        }
+
+    }
+
+    public enum ConnectorVertexType
+    {
+        None,
+        Start,
+        End,
     }
 }