Question

我有一个使用XmlSerializer进行序列化的类。除了其他属性，我还需要在对象中添加一块预先构建的xml。我已经在这篇文章中询问过如何处理xml：How to remove empty namespace attribute on manually added xml string when serializing object?

现在我需要为包含xml字符串的属性添加一个属性。我理解如何将属性添加到类而不是属性。如果我创建一个新类来保存属性，我会在输出中获得额外的层次结构。

这是我的简化代码：

public class Book
{
    public string Title { get; set; }

    public string Author { get; set; }

    public XmlElement Extension { get; set; }

    public Book()
    {
    }

    public void AddExtension()
    {
        string xmlString = "<AdditionalInfo xmlns=\"http://www.somenamespace.com\">" +
                                "<SpecialHandling>Some Value</SpecialHandling>" +
                           "</AdditionalInfo>";

        this.Extension = GetElement(xmlString);
    }

    public static XmlElement GetElement(string xml)
    {
        XmlDocument doc = new XmlDocument();

        doc.LoadXml(xml);

        return doc.DocumentElement;
    }
}

static void Main(string[] args)
{
    TestSerialization p = new TestSerialization();

    Book bookOne = new Book();

    bookOne.Title = "How to Fix Code";
    bookOne.Author = "Dee Bugger";

    bookOne.AddExtension();

    System.Xml.Serialization.XmlSerializer serializer = new XmlSerializer(typeof(Book), "http://www.somenamespace.com");

    using (var writer = new StreamWriter("C:\\BookReport.xml"))
    using (var xmlWriter = XmlWriter.Create(writer, new XmlWriterSettings { Indent = true }))
    {
        serializer.Serialize(xmlWriter, bookOne);
    }
}

它会生成以下输出：

<?xml version="1.0" encoding="utf-8"?>
<Book xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.somenamespace.com">
  <Title>How to Fix Code</Title>
  <Author>Dee Bugger</Author>
  <Extension>
    <AdditionalInfo xmlns="http://www.somenamespace.com">
      <SpecialHandling>Some Value</SpecialHandling>
    </AdditionalInfo>
  </Extension>
</Book>

现在我需要向Extension添加一个属性，使Extension输出看起来像：

...
<Extension Modifier="ABC">
    <AdditionalInfo xmlns="http://www.somenamespace.com">
      <SpecialHandling>Some Value</SpecialHandling>
    </AdditionalInfo>
</Extension>

有没有办法更改Book类来执行此操作？我试图创建一个Extension类来保存Modifier属性和xml字符串的XmlElement，但这导致了一个额外的级别：

public class Extension
{
    [XmlAttribute]
    public string Modifier { get; set; }

    [XmlElementAttribute("Extension")]
    public XmlElement ExtensionAsElement { get; set; }

    public Extension()
    {
    }

    public Extension(XmlElement extensionAsElement)
    {
        this.Modifier = "ABC";

        this.ExtensionAsElement = extensionAsElement;
    }
}

public class Book
{
    public string Title { get; set; }

    public string Author { get; set; }

    [XmlElementAttribute("Extension")]
    public Extension ExtensionObj { get; set; }

    public Book()
    {
    }

    public void AddExtension()
    {
        string xmlString = "<AdditionalInfo xmlns=\"http://www.somenamespace.com\">" +
                                "<SpecialHandling>Some Value</SpecialHandling>" +
                           "</AdditionalInfo>";

        this.ExtensionObj = new Extension(GetElement(xmlString));
    }

    public static XmlElement GetElement(string xml)
    {
        XmlDocument doc = new XmlDocument();

        doc.LoadXml(xml);

        return doc.DocumentElement;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<Book xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.somenamespace.com">
  <Title>How to Fix Code</Title>
  <Author>Dee Bugger</Author>
  <Extension Modifier="ABC">
    <Extension>
      <AdditionalInfo xmlns="http://www.somenamespace.com">
        <SpecialHandling>Some Value</SpecialHandling>
      </AdditionalInfo>
    </Extension>
  </Extension>
</Book>

注意：这是我的代码的一个过于简化的示例，Book类不是我的根。我只需要序列化，而不是反序列化。

Answer 1

您可以使用[XmlAnyElement("Extension")]指定您的Extension属性应该作为元素<Extension>本身插入到XML流中，而不是作为子< / em>该名称的元素。完成后，您将能够使用SetAttribute()和GetAttribute()在元素本身上设置属性。

因此，您的Book类变为：

public class Book { public string Title { get; set; } public string Author { get; set; } [XmlAnyElement("Extension")] public XmlElement Extension { get; set; } public Book() { this.Extension = new XmlDocument().CreateElement("Extension"); } public Book AddExtension() { string innerXmlString = "<AdditionalInfo xmlns=\"http://www.somenamespace.com\">" + "<SpecialHandling>Some Value</SpecialHandling>" + "</AdditionalInfo>"; if (Extension == null) // Since Extension is marked with [XmlAnyElement("Extension")], its value must // be an XmlElement named "Extension". Its InnerXml can be anything. Extension = new XmlDocument().CreateElement("Extension"); Extension.InnerXml = innerXmlString; return this; } const string ModifierName = "Modifier"; [XmlIgnore] public string Modifier { get { if (Extension == null) return null; return Extension.GetAttribute(ModifierName); } set { if (Extension == null) AddExtension(); if (value == null) Extension.RemoveAttribute(ModifierName); else Extension.SetAttribute(ModifierName, value); } } }

从以下内容创建XML：

var bookOne = new Book { Title = "How to Fix Code", Author = "Dee Bugger", Modifier = "AAA" } .AddExtension();

产生结果：

<Book xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Title>How to Fix Code</Title> <Author>Dee Bugger</Author> <Extension Modifier="AAA"> <AdditionalInfo xmlns="http://www.somenamespace.com"> <SpecialHandling>Some Value</SpecialHandling> </AdditionalInfo> </Extension> </Book>

如何序列化属性的属性或跳过类层次结构

1 个答案: