如何删除所有空XElements

时间:2012-06-15 14:16:33

标签: c# xml recursion linq-to-xml

这个有点棘手。说我有这个XmlDocument

<Object>
    <Property1>1</Property1>
    <Property2>2</Property2>
    <SubObject>
         <DeeplyNestedObject />
    </SubObject>
</Object>

我想回到这个

<Object>
    <Property1>1</Property1>
    <Property2>2</Property2>
</Object>

由于<SubObject>的每个孩子都是空元素,我想摆脱它。令您难以接受的是,当您重复遍历节点时,您无法删除它们。任何帮助将不胜感激。

更新以下是我的最新消息。

public XDocument Process()
{
    //Load my XDocument
    var xmlDoc = GetObjectXml(_source);

    //Keep track of empty elements
    var childrenToDelete = new List<XElement>();

    //Recursively iterate through each child node
    foreach (var node in xmlDoc.Root.Elements())
        Process(node, childrenToDelete);

    //An items marked for deletion can safely be removed here
    //Since we're not iterating over the source elements collection
    foreach (var deletion in childrenToDelete)
        deletion.Remove();

    return xmlDoc;
}

private void Process(XElement node, List<XElement> elementsToDelete)
{
    //Walk the child elements
    if (node.HasElements)
    {
        //This is the collection of child elements to be deleted 
        //for this particular node
        var childrenToDelete = new List<XElement>();

        //Recursively iterate each child
        foreach (var child in node.Elements())
            Process(child, childrenToDelete);

        //Delete all children that were marked as empty
        foreach (var deletion in childrenToDelete)
            deletion.Remove();

        //Since we just removed all this nodes empty children
        //delete it if there's nothing left
        if (node.IsEmpty)
            elementsToDelete.Add(node);
    }

    //The current leaf node is empty so mark it for deletion
    else if (node.IsEmpty)
        elementsToDelete.Add(node);
}

如果有人对此用例感兴趣,那么我会将ObjectFilter项目放在一起。

2 个答案:

答案 0 :(得分:9)

这会很慢,但你可以这样做:

XElement xml;
while (true) {
    var empties = xml.Descendants().Where(x => x.IsEmpty && !x.HasAttributes).ToList();
    if (empties.Count == 0)
        break;

    empties.ForEach(e => e.Remove());
}

为了加快速度,你可以在第一次迭代后走上父节点,看看它们是否为空。

XElement xml;
var empties = xml.Descendants().Where(x => x.IsEmpty && !x.HasAttributes).ToList();
while (empties.Count > 0) {
    var parents = empties.Select(e => e.Parent)
                         .Where(e => e != null)
                         .Distinct()    //In case we have two empty siblings, don't try to remove the parent twice
                         .ToList();

    empties.ForEach(e => e.Remove());

    //Filter the parent nodes to the ones that just became empty.
    parents.RemoveAll(e => e.IsEmpty && !e.HasAttributes);
    empties = parents;
}

答案 1 :(得分:-1)

这里我创建了一个XML文件,我在其中放入了所有xml代码。您还可以使用XmlLoad("")来加载xml。这将使用文件加载代码。您也可以尝试使用XmlLoad。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load("Test.xml");
            XmlElement root = doc.DocumentElement;
            foreach (var item in root)
            {
                XmlElement elem = (XmlElement)item;
                if (elem.InnerText.Equals(""))
                {
                    foreach (var child in elem.ChildNodes)
                    {
                        XmlElement childelem = (XmlElement)child;
                        childelem.RemoveAll();
                    }

                    elem.ParentNode.RemoveChild(elem);
                }
            }
            doc.Save("Test.xml");
            Console.ReadLine();
        }
    }
}