在 C# 中将特殊字符添加到 XML innertext 时的转换

Question

在写内文的时候需要用到特殊字符的十六进制编码，但是无法添加。我尝试了一些编码更改，但它不起作用。我需要像

这样的输出

–CO–OR 而不是 "–CO–OR"

"+" 而不是 "+"

下面提供了我尝试转换的代码。

else
{
  //convertedStr = System.Net.WebUtility.HtmlDecode(runText);
  Encoding iso = Encoding.Default; 
  Encoding utf8 = Encoding.Unicode;
  byte[] utfBytes = utf8.GetBytes(runText);
  byte[] isoBytes = Encoding.Convert(iso, utf8, utfBytes);
  string msg = iso.GetString(isoBytes);    
  eqnPartElm = clsGlobal.XMLDoc.CreateElement("inf");
  eqnPartElm.InnerText = msg;
  eqnElm.AppendChild(eqnPartElm);   
}

Answer 1

Unicode 字符的转义不受 XmlDocument 控制。相反，XmlWriter will escape characters not supported by the current encoding, as specified by XmlWriterSettings.Encoding, at the time the document is written to a stream. If you want all "special characters" such as the En Dash to be escaped, choose a very restrictive encoding such as Encoding.ASCII.

要轻松做到这一点，请创建以下扩展方法：

public static class XmlSerializationHelper
{
    public static string GetOuterXml(this XmlNode node, bool indent = false, Encoding encoding = null, bool omitXmlDeclaration = false)
    {
        if (node == null)
            return null;
        using var stream = new MemoryStream();
        node.Save(stream, indent : indent, encoding : encoding, omitXmlDeclaration : omitXmlDeclaration, closeOutput : false);
        stream.Position = 0;
        using var reader = new StreamReader(stream);
        return reader.ReadToEnd();
    }

    public static void Save(this XmlNode node, Stream stream, bool indent = false, Encoding encoding = null, bool omitXmlDeclaration = false, bool closeOutput = true) =>
        node.Save(stream, new XmlWriterSettings
                  {
                      Indent = indent,
                      Encoding = encoding,
                      OmitXmlDeclaration = omitXmlDeclaration,
                      CloseOutput = closeOutput,
                  });

    public static void Save(this XmlNode node, Stream stream, XmlWriterSettings settings)
    {
        using (var xmlWriter = XmlWriter.Create(stream, settings))
        {
            node.WriteTo(xmlWriter);
        }
    }
}

现在您可以执行以下操作，将 XmlDocument 序列化为转义了 non-ASCII 个字符的字符串：

// Construct your XmlDocument (not shown in the question)
var xmlDoc = new XmlDocument();
xmlDoc.LoadXml("<Root></Root>");
var eqnPartElm = xmlDoc.CreateElement("inf");
xmlDoc.DocumentElement.AppendChild(eqnPartElm);

// Add some non-ASCII text (here – is an En Dash character).
eqnPartElm.InnerText = "–CO–OR";

// Output to XML and escape all non-ASCII characters.
var xml = xmlDoc.GetOuterXml(indent : true, encoding : Encoding.ASCII, omitXmlDeclaration : true);

要序列化为 Stream，请执行：

using (var stream = new FileStream(fileName, FileMode.OpenOrCreate))
{
    xmlDoc.Save(stream, indent : true, encoding : Encoding.ASCII, omitXmlDeclaration : true);
}

并且将创建以下 XML：

<Root>
  <inf>&#x2013;CO&#x2013;OR</inf>
</Root>

请注意，您必须使用新的 XmlWriter 而不是旧的 XmlTextWriter，因为后者不支持用转义后备替换不受支持的字符。

演示 fiddle here.

在 C# 中将特殊字符添加到 XML innertext 时的转换

Conversion of the special characters while adding it to the XML innertext in C#

c#

xml

character-encoding