如何使用 XmlSerializer 将字符串序列化为 CDATA？

Question

是否可以通过某种属性使用 .Net XmlSerializer 将字符串序列化为 CDATA？

Answer 1

[Serializable]
public class MyClass
{
    public MyClass() { }

    [XmlIgnore]
    public string MyString { get; set; }
    [XmlElement("MyString")]
    public System.Xml.XmlCDataSection MyStringCDATA
    {
        get
        {
            return new System.Xml.XmlDocument().CreateCDataSection(MyString);
        }
        set
        {
            MyString = value.Value;
        }
    }
}

用法：

MyClass mc = new MyClass();
mc.MyString = "<test>Hello World</test>";
XmlSerializer serializer = new XmlSerializer(typeof(MyClass));
StringWriter writer = new StringWriter();
serializer.Serialize(writer, mc);
Console.WriteLine(writer.ToString());

输出：

<?xml version="1.0" encoding="utf-16"?>
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <MyString><![CDATA[<test>Hello World</test>]]></MyString>
</MyClass>

Answer 2

除了 John Saunders 发布的方式之外，您还可以直接使用XmlCDataSection作为类型，尽管它归结为几乎相同的事情：

private string _message;
[XmlElement("CDataElement")]
public XmlCDataSection Message
{  
    get 
    { 
        XmlDocument doc = new XmlDocument();
        return doc.CreateCDataSection( _message);
    }
    set
    {
        _message = value.Value;
    }
}

Answer 3

[XmlRoot("root")]
public class Sample1Xml
{
    internal Sample1Xml()
    {
    }

    [XmlElement("node")]
    public NodeType Node { get; set; }

    #region Nested type: NodeType

    public class NodeType
    {
        [XmlAttribute("attr1")]
        public string Attr1 { get; set; }

        [XmlAttribute("attr2")]
        public string Attr2 { get; set; }

        [XmlIgnore]
        public string Content { get; set; }

        [XmlText]
        public XmlNode[] CDataContent
        {
            get
            {
                var dummy = new XmlDocument();
                return new XmlNode[] {dummy.CreateCDataSection(Content)};
            }
            set
            {
                if (value == null)
                {
                    Content = null;
                    return;
                }

                if (value.Length != 1)
                {
                    throw new InvalidOperationException(
                        String.Format(
                            "Invalid array length {0}", value.Length));
                }

                Content = value[0].Value;
            }
        }
    }

    #endregion
}

Answer 4

在要序列化的类中：

public CData Content { get; set; }

和 CData 类：

public class CData : IXmlSerializable
{
    private string _value;

    /// <summary>
    /// Allow direct assignment from string:
    /// CData cdata = "abc";
    /// </summary>
    /// <param name="value">The string being cast to CData.</param>
    /// <returns>A CData object</returns>
    public static implicit operator CData(string value)
    {
        return new CData(value);
    }

    /// <summary>
    /// Allow direct assignment to string:
    /// string str = cdata;
    /// </summary>
    /// <param name="cdata">The CData being cast to a string</param>
    /// <returns>A string representation of the CData object</returns>
    public static implicit operator string(CData cdata)
    {
        return cdata._value;
    }

    public CData() : this(string.Empty)
    {
    }

    public CData(string value)
    {
        _value = value;
    }

    public override string ToString()
    {
        return _value;
    }

    public System.Xml.Schema.XmlSchema GetSchema()
    {
        return null;
    }

    public void ReadXml(System.Xml.XmlReader reader)
    {
        _value = reader.ReadElementString();
    }

    public void WriteXml(System.Xml.XmlWriter writer)
    {
        writer.WriteCData(_value);
    }
}

Answer 5

我有类似的需求，但需要不同的输出格式 - 我想要包含 CDATA 的节点上的属性。 我从上述解决方案中汲取了一些灵感来创建自己的解决方案。 也许它会在未来帮助某人......

public class EmbedScript
{
    [XmlAttribute("type")]
    public string Type { get; set; }

    [XmlText]
    public XmlNode[] Script { get; set; }

    public EmbedScript(string type, string script)
    {
        Type = type;
        Script = new XmlNode[] { new XmlDocument().CreateCDataSection(script) };
    }

    public EmbedScript()
    {

    }
}

在要序列化的父对象中，我具有以下属性：

    [XmlArray("embedScripts")]
    [XmlArrayItem("embedScript")]
    public List<EmbedScript> EmbedScripts { get; set; }

我得到以下输出：

<embedScripts>
    <embedScript type="Desktop Iframe">
        <![CDATA[<div id="play_game"><iframe height="100%" src="http://www.myurl.com" width="100%"></iframe></div>]]>
    </embedScript>
    <embedScript type="JavaScript">
        <![CDATA[]]>
    </embedScript>
</embedScripts>

Answer 6

在我的情况下，我使用的是混合字段，有些 CDATA 有些不是，至少对我来说，以下解决方案是有效的....

通过始终阅读 Value 字段，我得到了内容，无论是 CDATA 还是纯文本。

    [XmlElement("")]
    public XmlCDataSection CDataValue {
        get {
            return new XmlDocument().CreateCDataSection(this.Value);
        }
        set {
            this.Value = value.Value;
        }
    }

    [XmlText]
    public string Value;

迟到总比不到好。

干杯

Answer 7

此实现能够处理您正在编码的字符串中的嵌套 CDATA（基于 John Saunders 的原始答案）。

例如，假设您想将以下文字字符串编码为 CDATA：

I am purposefully putting some <![CDATA[ cdata markers right ]]> in here!!

您希望结果输出如下所示：

<![CDATA[I am purposefully putting some <![CDATA[ cdata markers right ]]]]><![CDATA[> in here!!]]>

下面的实现将遍历字符串，将...]]>...实例拆分为...]]和>...并为每个创建单独的 CDATA 部分。

[XmlRoot("root")]
public class Sample1Xml
{
    internal Sample1Xml()
    {
    }

    [XmlElement("node")]
    public NodeType Node { get; set; }

    #region Nested type: NodeType

    public class NodeType
    {
        [XmlAttribute("attr1")]
        public string Attr1 { get; set; }

        [XmlAttribute("attr2")]
        public string Attr2 { get; set; }

        [XmlIgnore]
        public string Content { get; set; }

        [XmlText]
        public XmlNode[] CDataContent
        {
            get
            {
                XmlDocument dummy = new XmlDocument();
                List<XmlNode> xmlNodes = new List<XmlNode>();
                int tokenCount = 0;
                int prevSplit = 0;
                for (int i = 0; i < Content.Length; i++)
                {
                    char c = Content[i];
                    //If the current character is > and it was preceded by ]] (i.e. the last 3 characters were ]]>)
                    if (c == '>' && tokenCount >= 2)
                    {
                        //Put everything up to this point in a new CData Section
                        string thisSection = Content.Substring(prevSplit, i - prevSplit);
                        xmlNodes.Add(dummy.CreateCDataSection(thisSection));
                        prevSplit = i;
                    }
                    if (c == ']')
                    {
                        tokenCount++;
                    }
                    else
                    {
                        tokenCount = 0;
                    }
                }
                //Put the final part of the string into a CData section
                string finalSection = Content.Substring(prevSplit, Content.Length - prevSplit);
                xmlNodes.Add(dummy.CreateCDataSection(finalSection));

                return xmlNodes.ToArray();
            }
            set
            {
                if (value == null)
                {
                    Content = null;
                    return;
                }

                if (value.Length != 1)
                {
                    throw new InvalidOperationException(
                        String.Format(
                            "Invalid array length {0}", value.Length));
                }

                Content = value[0].Value;
            }
        }
    }

Answer 8

这很好用

using System.Collections.ObjectModel;
using System.Linq;
using System.Xml;
using System.Xml.Serialization;

public class CDataContent
{
    public CDataContent()
    {
    }

    public CDataContent(string content)
    {
        this.Content = content;
    }

    [XmlIgnore]
    public string Content
    {
        get => this.CData.FirstOrDefault()?.Value;
        set
        {
            this.CData.Clear();
            this.CData.Add(new XmlDocument().CreateCDataSection(value));
        }
    }

    [XmlText]
    public Collection<XmlNode> CData { get; } = new();

    public static implicit operator CDataContent(string value) => new(value);

    public static implicit operator string(CDataContent value) => value.Content;
}