如何使用LINQ或XPath从XML打印值

Question

我使用XPath或LINQ获取从XML打印的值也很困难，这也是XPath和XML Parsing的新增内容，在这里看了几个示例，但没有任何帮助，因为它们都具有不同属性名称的XML，对于我的情况，XML是不同的：

<Entities TotalResult="3">
    <Entity Type="test-set-folder">
      <Fields>
          <Field Name="id">
            <Value>12457</Value>
          </Field>
          <Field Name="parent-id">
            <Value>0</Value>
          </Field>
          <Field Name="last-modified">
            <Value>2015-03-09 14:09:57</Value>
          </Field>
          <Field Name="description">
             <Value/>
          </Field>
          <Field Name="view-order"/>
          <Field Name="name">
            <Value>.NET</Value>
          </Field>
     </Fields>
   </Entity>
   <Entity Type="test-set-folder">
     <Fields>
        <Field Name="id">
           <Value>15487</Value>
        </Field>
        <Field Name="parent-id">
          <Value>0</Value>
        </Field>
        <Field Name="last-modified">
          <Value>2015-03-15 13:00:02</Value>
        </Field>
        <Field Name="description">
          <Value/>
        </Field>
        <Field Name="view-order"/>
        <Field Name="name">
          <Value>Python</Value>
        </Field>
     </Fields>
  </Entity>
</Entities>

它具有相同的属性Field但Name不同。

有人可以帮我打印属性Name及其Value 。

我需要遍历每个Entity并打印其Name : Value 。

到目前为止，我尝试过使用Xpath和LINQ：

var doc = XDocument.Load("XMLFile1.xml");
        foreach (var child in doc.Element("Field Name").Elements())
        {
            Console.WriteLine(child.Name);
        } 

但严重的是我对此并不太了解，所以我的方法完全错了。

我的预期输出是：

Id: 12457
parent-id: 0
last-modified:2015-03-09 14:09:57
description:
view-order:
name: .NET

并且对于下一个实体也是如此。

Answer 1

由于某些Fields缺少Value元素，您可以尝试这样做：

XElement element = XElement.Load("XmlFile.xml"); 
var query = from field in element.Descendants("Field")
select new
{
    NameAttribute = field.Attribute("Name").Value,
    Value = field.Descendants("Value").Any() ?
    field.Element("Value").Value : "No Value"
};
var namesAndValues = query.ToList()

Answer 2

您有一个数据透视表，因为您的数据是从两个标记（名称和值）中提取的。 这是一种解析xml的方法

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Entity> cEntities = new List<Entity>();
            string input =
                "<Entities TotalResult=\"3\">" +
                    "<Entity Type=\"test-set-folder\">" +
                      "<Fields>" +
                          "<Field Name=\"id\">" +
                            "<Value>12457</Value>" +
                          "</Field>" +
                          "<Field Name=\"parent-id\">" +
                            "<Value>0</Value>" +
                          "</Field>" +
                          "<Field Name=\"last-modified\">" +
                            "<Value>2015-03-09 14:09:57</Value>" +
                          "</Field>" +
                          "<Field Name=\"description\">" +
                             "<Value/>" +
                          "</Field>" +
                          "<Field Name=\"view-order\"/>" +
                          "<Field Name=\"name\">" +
                            "<Value>.NET</Value>" +
                          "</Field>" +
                     "</Fields>" +
                   "</Entity>" +
                   "<Entity Type=\"test-set-folder\">" +
                     "<Fields>" +
                        "<Field Name=\"id\">" +
                           "<Value>15487</Value>" +
                        "</Field>" +
                        "<Field Name=\"parent-id\">" +
                          "<Value>0</Value>" +
                        "</Field>" +
                        "<Field Name=\"last-modified\">" +
                          "<Value>2015-03-15 13:00:02</Value>" +
                        "</Field>" +
                        "<Field Name=\"description\">" +
                          "<Value/>" +
                        "</Field>" +
                        "<Field Name=\"view-order\"/>" +
                        "<Field Name=\"name\">" +
                          "<Value>Python</Value>" +
                        "</Field>" +
                     "</Fields>" +
                  "</Entity>" +
                "</Entities>";


            XElement entities = XElement.Parse(input);

            foreach (XElement entity in entities.Descendants("Entity"))
            {
                Entity newEntity = new Entity();
                cEntities.Add(newEntity);

                foreach (XElement field in entity.Descendants("Field"))
                {
                    string name = field.Attribute("Name").Value;
                    string value = field.Element("Value") == null ? "" : field.Element("Value").Value;

                    switch (name)
                    {
                        case "id" :
                            newEntity.id = int.Parse(value);
                            break;
                        case "parent-id":
                            newEntity.parent_id = int.Parse(value);
                            break;
                        case "last-modified":
                            newEntity.last_modified = DateTime.Parse(value);
                            break;
                        case "description":
                            newEntity.description = value;
                            break;
                        case "view-order":
                            newEntity.view_order = value;
                            break;
                        case "name":
                            newEntity.name = value;
                            break;
                    }
                }
            }

            //write data
            foreach(Entity entity in cEntities)
            {
                Console.WriteLine("id: {0}", entity.id);
                Console.WriteLine("parent-id: {0}", entity.parent_id);
                Console.WriteLine("last-modified: {0}",entity.last_modified);
                Console.WriteLine("description: {0}",entity.description);
                Console.WriteLine("view-order: {0}",entity.view_order);
                Console.WriteLine("name: {0}",entity.name);
                Console.WriteLine();

            }
            Console.ReadLine();


        }
        public class Entity
        {
            public int id { get; set; }
            public int parent_id { get; set; }
            public DateTime last_modified { get; set; }
            public string description { get; set; }
            public string view_order { get; set; }
            public string name { get; set; }
        }
    }
}
​

Answer 3

您只需要遵循xml的结构

未经测试的代码：

var doc = XDocument.Load("XMLFile1.xml");
foreach (var fields in doc.Descendants("Fields")) {

    foreach (var field in fields.Elements("Field")) {

        Debug.WriteLine(string.Format("{0}: {1}", field.Attribute("Name").Value, field.Elements("Value").First().Value));

    }

}

Answer 4

尝试这个

var names = from r in document.Descendants("Entities")
                                .Descendants("Entity")
                                    .Descendants("Fields")
                                        .Descendants("Field")
            select new
                {
                    Name = r.Element("name").Value,
                };

foreach (var n in names)
{
    Console.WriteLine(n.Name);
}