格式化 XML 字符串以打印友好的 XML 字符串

Question

我有一个这样的 XML 字符串：

<?xml version='1.0'?><response><error code='1'> Success</error></response>

一个元素和另一个元素之间没有线，因此很难阅读。我想要一个格式化上述字符串的函数：

<?xml version='1.0'?>
<response>
<error code='1'> Success</error>
</response> 

不用自己手动编写格式化函数，有没有什么.Net库或者代码sn-p可以随便用？

Answer 1

您必须以某种方式解析内容……我发现使用 LINQ 是最简单的方法。同样，这完全取决于您的具体情况。这是一个使用 LINQ 格式化输入 XML 字符串的工作示例。

string FormatXml(string xml)
{
     try
     {
         XDocument doc = XDocument.Parse(xml);
         return doc.ToString();
     }
     catch (Exception)
     {
         // Handle and throw if fatal exception here; don't just ignore them
         return xml;
     }
 }

[为简洁起见省略使用语句]

Answer 2

使用XmlTextWriter...

public static string PrintXML(string xml)
{
    string result = "";

    MemoryStream mStream = new MemoryStream();
    XmlTextWriter writer = new XmlTextWriter(mStream, Encoding.Unicode);
    XmlDocument document = new XmlDocument();

    try
    {
        // Load the XmlDocument with the XML.
        document.LoadXml(xml);

        writer.Formatting = Formatting.Indented;

        // Write the XML into a formatting XmlTextWriter
        document.WriteContentTo(writer);
        writer.Flush();
        mStream.Flush();

        // Have to rewind the MemoryStream in order to read
        // its contents.
        mStream.Position = 0;

        // Read MemoryStream contents into a StreamReader.
        StreamReader sReader = new StreamReader(mStream);

        // Extract the text from the StreamReader.
        string formattedXml = sReader.ReadToEnd();

        result = formattedXml;
    }
    catch (XmlException)
    {
        // Handle the exception
    }

    mStream.Close();
    writer.Close();

    return result;
}

Answer 3

This one, from kristopherjohnson 更好：

1. 它也不需要 XML 文档标题。
2. 有更清晰的异常
3. 添加额外的行为选项：OmitXmlDeclaration = true, NewLineOnAttributes = true

4. 代码行数更少

   static string PrettyXml(string xml)
   {
       var stringBuilder = new StringBuilder();
   
       var element = XElement.Parse(xml);
   
       var settings = new XmlWriterSettings();
       settings.OmitXmlDeclaration = true;
       settings.Indent = true;
       settings.NewLineOnAttributes = true;
   
       using (var xmlWriter = XmlWriter.Create(stringBuilder, settings))
       {
           element.Save(xmlWriter);
       }
   
       return stringBuilder.ToString();
   }
   

Answer 4

对我有用的简单解决方案：

        XmlDocument xmlDoc = new XmlDocument();
        StringWriter sw = new StringWriter();
        xmlDoc.LoadXml(rawStringXML);
        xmlDoc.Save(sw);
        String formattedXml = sw.ToString();

Answer 5

检查以下链接：How to pretty-print XML（不幸的是，该链接现在返回 404 :()

链接中的方法将 XML 字符串作为参数并返回格式正确（缩进）的 XML 字符串。

我只是从链接中复制了示例代码，以使这个答案更加全面和方便。

public static String PrettyPrint(String XML)
{
    String Result = "";

    MemoryStream MS = new MemoryStream();
    XmlTextWriter W = new XmlTextWriter(MS, Encoding.Unicode);
    XmlDocument D   = new XmlDocument();

    try
    {
        // Load the XmlDocument with the XML.
        D.LoadXml(XML);

        W.Formatting = Formatting.Indented;

        // Write the XML into a formatting XmlTextWriter
        D.WriteContentTo(W);
        W.Flush();
        MS.Flush();

        // Have to rewind the MemoryStream in order to read
        // its contents.
        MS.Position = 0;

        // Read MemoryStream contents into a StreamReader.
        StreamReader SR = new StreamReader(MS);

        // Extract the text from the StreamReader.
        String FormattedXML = SR.ReadToEnd();

        Result = FormattedXML;
    }
    catch (XmlException)
    {
    }

    MS.Close();
    W.Close();

    return Result;
}

Answer 6

我试过了：

internal static void IndentedNewWSDLString(string filePath)
{
    var xml = File.ReadAllText(filePath);
    XDocument doc = XDocument.Parse(xml);
    File.WriteAllText(filePath, doc.ToString());
}

一切正常。

Answer 7

.NET 2.0 忽略名称解析，并使用适当的资源处置、缩进、保留空白和自定义编码：

public static string Beautify(System.Xml.XmlDocument doc)
{
    string strRetValue = null;
    System.Text.Encoding enc = System.Text.Encoding.UTF8;
    // enc = new System.Text.UTF8Encoding(false);

    System.Xml.XmlWriterSettings xmlWriterSettings = new System.Xml.XmlWriterSettings();
    xmlWriterSettings.Encoding = enc;
    xmlWriterSettings.Indent = true;
    xmlWriterSettings.IndentChars = "    ";
    xmlWriterSettings.NewLineChars = "\r\n";
    xmlWriterSettings.NewLineHandling = System.Xml.NewLineHandling.Replace;
    //xmlWriterSettings.OmitXmlDeclaration = true;
    xmlWriterSettings.ConformanceLevel = System.Xml.ConformanceLevel.Document;


    using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
    {
        using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(ms, xmlWriterSettings))
        {
            doc.Save(writer);
            writer.Flush();
            ms.Flush();

            writer.Close();
        } // End Using writer

        ms.Position = 0;
        using (System.IO.StreamReader sr = new System.IO.StreamReader(ms, enc))
        {
            // Extract the text from the StreamReader.
            strRetValue = sr.ReadToEnd();

            sr.Close();
        } // End Using sr

        ms.Close();
    } // End Using ms


    /*
    System.Text.StringBuilder sb = new System.Text.StringBuilder(); // Always yields UTF-16, no matter the set encoding
    using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(sb, settings))
    {
        doc.Save(writer);
        writer.Close();
    } // End Using writer
    strRetValue = sb.ToString();
    sb.Length = 0;
    sb = null;
    */

    xmlWriterSettings = null;
    return strRetValue;
} // End Function Beautify

用法：

System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
xmlDoc.XmlResolver = null;
xmlDoc.PreserveWhitespace = true;
xmlDoc.Load("C:\Test.svg");
string SVG = Beautify(xmlDoc);

Answer 8

带有 UTF-8 XML 声明的可自定义 Pretty XML 输出

以下类定义提供了一个简单的方法，用于将输入 XML 字符串转换为格式化的输出 XML，xml 声明为 UTF-8。它支持XmlWriterSettings 类提供的所有配置选项。

using System;
using System.Text;
using System.Xml;
using System.IO;

namespace CJBS.Demo
{
    /// <summary>
    /// Supports formatting for XML in a format that is easily human-readable.
    /// </summary>
    public static class PrettyXmlFormatter
    {

        /// <summary>
        /// Generates formatted UTF-8 XML for the content in the <paramref name="doc"/>
        /// </summary>
        /// <param name="doc">XmlDocument for which content will be returned as a formatted string</param>
        /// <returns>Formatted (indented) XML string</returns>
        public static string GetPrettyXml(XmlDocument doc)
        {
            // Configure how XML is to be formatted
            XmlWriterSettings settings = new XmlWriterSettings 
            {
                Indent = true
                , IndentChars = "  "
                , NewLineChars = System.Environment.NewLine
                , NewLineHandling = NewLineHandling.Replace
                //,NewLineOnAttributes = true
                //,OmitXmlDeclaration = false
            };

            // Use wrapper class that supports UTF-8 encoding
            StringWriterWithEncoding sw = new StringWriterWithEncoding(Encoding.UTF8);

            // Output formatted XML to StringWriter
            using (XmlWriter writer = XmlWriter.Create(sw, settings))
            {
                doc.Save(writer);
            }

            // Get formatted text from writer
            return sw.ToString();
        }



        /// <summary>
        /// Wrapper class around <see cref="StringWriter"/> that supports encoding.
        /// Attribution: http://stackoverflow.com/a/427737/3063884
        /// </summary>
        private sealed class StringWriterWithEncoding : StringWriter
        {
            private readonly Encoding encoding;

            /// <summary>
            /// Creates a new <see cref="PrettyXmlFormatter"/> with the specified encoding
            /// </summary>
            /// <param name="encoding"></param>
            public StringWriterWithEncoding(Encoding encoding)
            {
                this.encoding = encoding;
            }

            /// <summary>
            /// Encoding to use when dealing with text
            /// </summary>
            public override Encoding Encoding
            {
                get { return encoding; }
            }
        }
    }
}

进一步改进的可能性：-

• 可以创建一个额外的方法GetPrettyXml(XmlDocument doc, XmlWriterSettings settings)，允许调用者自定义输出。
• 可以添加一个额外的方法GetPrettyXml(String rawXml) 来支持解析原始文本，而不是让客户端使用 XmlDocument。在我的例子中，我需要使用 XmlDocument 来操作 XML，因此我没有添加它。

用法：

String myFormattedXml = null;
XmlDocument doc = new XmlDocument();
try
{
    doc.LoadXml(myRawXmlString);
    myFormattedXml = PrettyXmlFormatter.GetPrettyXml(doc);
}
catch(XmlException ex)
{
    // Failed to parse XML -- use original XML as formatted XML
    myFormattedXml = myRawXmlString;
}

Answer 9

查看以下链接：Format an XML file so it looks nice in C#

// Format the XML text.
StringWriter string_writer = new StringWriter();
XmlTextWriter xml_text_writer = new XmlTextWriter(string_writer);
xml_text_writer.Formatting = Formatting.Indented;
xml_document.WriteTo(xml_text_writer);

// Display the result.
txtResult.Text = string_writer.ToString();

Answer 10

如果您加载 XMLDoc，我很确定 .ToString() 函数对此有重载。

但是这是为了调试吗？以这样的方式发送它的原因是占用更少的空间（即从 XML 中去除不必要的空白）。

Answer 11

可以通过带有XmlWriter.WriteNode(XmlReader, true) 的流转换 漂亮地打印XML 字符串。这个方法

将所有内容从读取器复制到写入器，并将读取器移动到下一个兄弟的开头。

定义以下扩展方法：

public static class XmlExtensions
{
    public static string FormatXml(this string xml, bool indent = true, bool newLineOnAttributes = false, string indentChars = "  ", ConformanceLevel conformanceLevel = ConformanceLevel.Document) => 
        xml.FormatXml( new XmlWriterSettings { Indent = indent, NewLineOnAttributes = newLineOnAttributes, IndentChars = indentChars, ConformanceLevel = conformanceLevel });

    public static string FormatXml(this string xml, XmlWriterSettings settings)
    {
        using (var textReader = new StringReader(xml))
        using (var xmlReader = XmlReader.Create(textReader, new XmlReaderSettings { ConformanceLevel = settings.ConformanceLevel } ))
        using (var textWriter = new StringWriter())
        {
            using (var xmlWriter = XmlWriter.Create(textWriter, settings))
                xmlWriter.WriteNode(xmlReader, true);
            return textWriter.ToString();
        }
    }
}

现在你可以做到：

var inXml = @"<?xml version='1.0'?><response><error code='1'> Success</error></response>";
var newXml = inXml.FormatXml(indentChars : "", newLineOnAttributes : false); // Or true, if you prefer
Console.WriteLine(newXml);

打印出来的

<?xml version='1.0'?>
<response>
<error code="1"> Success</error>
</response>

注意事项：

• 其他答案将 XML 加载到一些 Document Object Model 中，例如 XmlDocument 或 XDocument/XElement，然后在启用缩进的情况下重新序列化 DOM。

  这种流式解决方案完全避免了 DOM 增加的内存开销。

• 在您的问题中，您没有为嵌套的<error code='1'> Success</error> 节点添加任何缩进，所以我设置了indentChars : ""。通常每层嵌套缩进两个空格。

• 如果当前是单引号，属性分隔符将无条件地转换为双引号。 （我相信其他答案也是如此。）

• 传递 conformanceLevel : ConformanceLevel.Fragment 允许格式化包含 XML 片段序列的字符串。

• 除了ConformanceLevel.Fragment，输入的 XML 字符串必须格式正确。如果不是，XmlReader 会抛出异常。

演示小提琴here.

Answer 12

嗨，你为什么不试试这个：

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.PreserveWhitespace = false;
....
....
xmlDoc.Save(fileName);

PreserveWhitespace = false;该选项也可以用于 xml 美化器。