◆ Advance()

override XPathNavigator MS.Internal.Xml.XPath.PrecedingQuery.Advance ( )
inline
Definition at line 33 of file PrecedingQuery.cs.
    {
        if (_workIterator == null)
        {
            XPathNavigator xPathNavigator = qyInput.Advance();
            if (xPathNavigator == null)
            {
                return null;
            }
            XPathNavigator xPathNavigator2 = xPathNavigator.Clone();
            do
            {
                xPathNavigator2.MoveTo(xPathNavigator);
            }
            while ((xPathNavigator = qyInput.Advance()) != null);
            if (xPathNavigator2.NodeType == XPathNodeType.Attribute || xPathNavigator2.NodeType == XPathNodeType.Namespace)
            {
                xPathNavigator2.MoveToParent();
            }
            do
            {
                _ancestorStk.Push(xPathNavigator2.Clone());
            }
            while (xPathNavigator2.MoveToParent());
            _workIterator = xPathNavigator2.SelectDescendants(XPathNodeType.All, matchSelf: true);
        }
        while (_workIterator.MoveNext())
        {
            currentNode = _workIterator.Current;
            if (currentNode.IsSamePosition(_ancestorStk.Peek()))
            {
                _ancestorStk.Pop();
                if (_ancestorStk.Count == 0)
                {
                    currentNode = null;
                    _workIterator = null;
                    return null;
                }
            }
            else if (matches(currentNode))
            {
                position++;
                return currentNode;
            }
        }
        return null;
    }