System.Xml.DocumentXPathNavigator.Compare C# (CSharp) Méthode

        private XmlNodeOrder Compare( XmlNode node1, XmlNode node2 ) {
            Debug.Assert( node1 != null );
            Debug.Assert( node2 != null );
            Debug.Assert( node1 != node2, "Should be handled by ComparePosition()" );
            //Attribute nodes come before other children nodes except namespace nodes
            Debug.Assert( OwnerNode(node1) == OwnerNode(node2) );
            if (node1.XPNodeType == XPathNodeType.Attribute) {
                if (node2.XPNodeType == XPathNodeType.Attribute) {
                    XmlElement element = ((XmlAttribute)node1).OwnerElement;
                    if (element.HasAttributes) {
                        XmlAttributeCollection attributes = element.Attributes;
                        for (int i = 0; i < attributes.Count; i++) {
                            XmlAttribute attribute = attributes[i];
                            if (attribute == node1) {
                                return XmlNodeOrder.Before;
                            }
                            else if (attribute == node2) {
                                return XmlNodeOrder.After;
                            }
                        }
                    }
                    return XmlNodeOrder.Unknown;
                }
                else {
                    return XmlNodeOrder.Before;
                }
            }
            if (node2.XPNodeType == XPathNodeType.Attribute) {
                return XmlNodeOrder.After;
            }
            
            //neither of the node is Namespace node or Attribute node
            XmlNode nextNode = node1.NextSibling;
            while ( nextNode != null && nextNode != node2 )
                nextNode = nextNode.NextSibling;
            if ( nextNode == null )
                //didn't meet node2 in the path to the end, thus it has to be in the front of node1
                return XmlNodeOrder.After;
            else
                //met node2 in the path to the end, so node1 is at front
                return XmlNodeOrder.Before;
        }