可以把连线从节点上拖下来，并且依附上去。

AIStudio.Wpf.DiagramDesigner/Controls/DesignerCanvas.cs

@@ -410,8 +410,8 @@ namespace AIStudio.Wpf.DiagramDesigner
 
                     if (EnableSnapping)
                     {
-                        var nearPort = FindNearPortToAttachTo();
-                        if (nearPort != null || partialConnection.SinkConnectorInfoFully != null)
+                        var nearPort = _viewModel.FindNearPortToAttachTo(partialConnection);
+                        if (nearPort != null)
                         {
                             partialConnection.SinkConnectorInfo = nearPort;
                         }
@@ -632,20 +632,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             e.Handled = true;
 
             this.Focus();
-        }
-
-        #region 自动依附节点
-        private FullyCreatedConnectorInfo FindNearPortToAttachTo()
-        {
-            foreach (var port in _viewModel.Items.OfType<DesignerItemViewModelBase>().ToList().SelectMany(n => n.Connectors))
-            {
-                if (partialConnection.OnGoingPosition.DistanceTo(port.Position) < SnappingRadius &&
-                    partialConnection.SourceConnectorInfoFully?.CanAttachTo(port) == true)
-                    return port;
-            }
-
-            return null;
-        }
-        #endregion
+        }       
     }
 }