连接线修改，为支持改变连接点做准备

Util.DiagramDesigner/UserControls/PointContainer.xaml.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Linq;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace Util.DiagramDesigner
+{
+    /// <summary>
+    /// PointContainer.xaml 的交互逻辑
+    /// </summary>
+    public partial class PointContainer : ItemsControl
+    {
+        public PointContainer()
+        {
+            InitializeComponent();
+        }
+    }
+}