Revert "Revert "block 可以拖拽到内部，还有少量问题待解决""

This reverts commit fcd7beb193.

AIStudio.Wpf.DiagramDesigner/Controls/BlockConnector.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+
+namespace AIStudio.Wpf.DiagramDesigner
+{
+    public class BlockConnector : ContentControl
+    {
+        public ConnectorOrientation Orientation { get; set; }
+
+        public ConnectorInfoBase Info
+        {
+            get
+            {
+                if (Content is ConnectorInfoBase connectorInfo)
+                    return connectorInfo;
+
+                return this.DataContext as ConnectorInfoBase;
+            }
+        }
+
+    }
+
+    public class BlockBorder : Border
+    {
+    }
+
+}