Question

我正在尝试通过在迭代候选节点集时从中删除节点来修改XmlDocument。我遇到的问题是，即使节点有206个元素，MoveNext（）在元素1之后返回false。

这可能是因为我正在修改数据吗？我怎么能绕过这个？还是我错过了其他原因？我的代码如下。

完成相同事情的任何其他方式（有选择地从XML文件中删除节点）也可以正常工作。

XmlReader reader = XmlReader.Create(myFile.FullName);

// Load document
XmlDocument document = new XmlDocument();
document.Load(reader);
XPathNavigator navigator = document.CreateNavigator();

// Select elementD nodes with the correct format (there are other elementD nodes that we 
// want to ignore
XPathNodeIterator nodes = navigator.Select("/elementA/elementB/elementC/elementB/elementD");

// Keep count of how many nodes we've deleted
int count = 0;

while (nodes.MoveNext)
{
moreNodes = nodes.MoveNext();

XPathNavigator node = nodes.Current;

logger.log(node.ToString());
string name = node.GetAttribute("name", "");

// If name isn't a valid name, delete it from the document
if (!validNames.Contains(name))
{
    count++;

    // Get the parent node (elementB)
    XPathNavigator elementBNode = node.SelectSingleNode("..");

    // And its parent node (elementC)
    XPathNavigator elementCNode = elementBNode.SelectSingleNode("..");

    // Delete the elementB node
    elementBNode.DeleteSelf();

    // It the elementC node is empty, then delete it as well
    if (!elementCNode.HasChildren)
    {
    elementCNode.DeleteSelf();
    }
}
}

// Make sure the document gets formatted nicely
XmlWriterSettings settings= new XmlWriterSettings();
settings.Indent = true;
settings.IndentChars = ("    ");

// Write out the modified document
XmlWriter writer = XmlWriter.Create(myFile + ".modified", settings);
document.WriteTo(writer);

Answer 1

来自documentation here（在“备注”下）：

使用XPathNodeIterator时，如果您编辑当前节点或任何节点它的祖先，你现在的位置丢失了。如果你想编辑一个您选择的节点数量，创建一个XPathNavigator数组，然后将XPathNodeIterator中的所有节点复制到数组中迭代数组并修改节点。

Answer 2

这是克隆要删除的元素的代码示例。

       XPathNodeIterator iteratorRef = nav.Select(path, namespaceManager);
       List<XPathNavigator> toDelete = new List<XPathNavigator>();

        while (iteratorRef.MoveNext())
        {
            bool condition = IsElementToDelete(iteratorRef);
            if (condition)
            {
                // It is important to clone Current otherwise you'll sameelement in toDelete 
                toDelete.Add(iteratorRef.Current.Clone());
            }
        }
        foreach (XPathNavigator xPathNavigator in toDelete)
        {
            xPathNavigator.DeleteSelf();
        }

使用XPathNodeIterator迭代它时修改XmlDocument

2 个答案: