从 XML 中选择节点并创建一个新的 XML

Question

我正在尝试剥离我的 XML 并仅保留 String Keep 数组中的节点

输入 XML 是

 <Employees>
  <Employee>
    <EmpId>1</EmpId>
    <Name>Sam</Name>
    <Sex>Male</Sex>
    <Address>
      <Country>USA</Country>
      <Zip>95220</Zip>
    </Address>
  </Employee>
  <Employee>
    <EmpId>2</EmpId>
    <Name>Lucy</Name>
    <Sex>Female</Sex>
    <Address>
      <Country>USA</Country>
      <Zip>95220</Zip>
    </Address>
  </Employee>
</Employees>

我需要的输出是

<Employees>
  <Employee>
    <EmpId>1</EmpId>
    <Sex>Male</Sex>
    <Address>
     <Zip>95220</Zip>
    </Address>
  </Employee>
  <Employee>
    <EmpId>2</EmpId>
    <Sex>Female</Sex>
    <Address>
      <Zip>95220</Zip>
    </Address>
  </Employee>
</Employees>

我的代码如下。

private void button1_Click(object sender, EventArgs e)
            {
                XmlDocument xDoc = new XmlDocument();

            xDoc.Load(XML_Path);
           // xDoc.Load();
            XmlNodeList xNodes = xDoc.SelectNodes("Employees/Employee");
            XmlDocument doc = new XmlDocument();
            XmlNode docNode = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
            doc.AppendChild(docNode);

            XmlNode employeesNode = doc.CreateElement("Employees");
            doc.AppendChild(employeesNode);
            string s =null;
            string keep = "EmpId,Sex,Address/Zip";
            string[] strArr = keep.Split(',');
            foreach(XmlNode xN in xNodes)
            {
                XmlNode employeeNode = doc.CreateElement("Employee");
                employeesNode.AppendChild(employeeNode);

                foreach (string str in strArr)
                {
                    XmlNode xNod = xN.SelectSingleNode(str);
                    employeeNode.AppendChild(xNod);

                }

            }
            richTextBox1.Text = doc.ToString();

        }

我在内部 foreach 循环中遇到一个奇怪的错误，它不会添加新节点，谁能告诉我我做错了什么。

谢谢

Answer 1

使用 Linq to Xml 试试这个，代码会非常简洁。

private void button1_Click(object sender, EventArgs e)
{
    var xDoc = XDocument.Load(XML_Path)
    string keep = "EmpId,Sex,Address,Zip";
    string[] strArr = keep.Split(',');

    var nodesToDelete = xDoc.Root.Descendants("Employee")
        .SelectMany(e => e.Descendants()
                          .Where(a => !strArr.Contains(a.Name.ToString())));

    foreach (var node in nodesToDelete.ToList())
        node.Remove();

    richTextBox1.Text = xDoc.ToString();
}

Answer 2

你可以这样做：

XmlDocument source = new XmlDocument();
source.LoadXml(xmldata);

var keep = new[] {"EmpId", "Sex", "Address/Zip"};
foreach (XmlElement employee in source.SelectNodes("/Employees/Employee"))
foreach (XmlElement child in employee.SelectNodes(".//*"))
{
    if(keep.Any(i => i.StartsWith(child.Name) || i.EndsWith(child.Name)))
        continue;

    child.ParentNode.RemoveChild(child);
}
Console.WriteLine(source.OuterXml);

但是，由于您的 keep 数组可能会更改并且可能需要不同的场景，您应该尝试使用 XSLT 转换。

Answer 3

使用 XDocument 怎么样？

下面的代码为您提供所需的输出。

string xmlString =
            @"<?xml version=""1.0""?>
            <Employees>
              <Employee>
                <EmpId>1</EmpId>
                <Name>Sam</Name>
                <Sex>Male</Sex>
                <Address>
                  <Country>USA</Country>
                  <Zip>95220</Zip>
                </Address>
              </Employee>
              <Employee>
                <EmpId>2</EmpId>
                <Name>Lucy</Name>
                <Sex>Female</Sex>
                <Address>
                  <Country>USA</Country>
                  <Zip>95220</Zip>
                </Address>
              </Employee>
            </Employees>
            ";

        System.Xml.Linq.XDocument xmlDoc = System.Xml.Linq.XDocument.Parse(xmlString);

        foreach (var employee in xmlDoc.Descendants("Employee"))
        {
            employee.Descendants("Name").First().Remove();

            employee.Descendants("Address").First().Descendants("Country").First().Remove();
        }

        MessageBox.Show(xmlDoc.ToString());