如何使用xml編寫器創建xml而不聲明元素

Question

我使用XmlWriter.Create()來獲取編寫器實例然後編寫XML，但結果是<?xml version="1.0" encoding="utf-16" ?>，我該如何告訴我的xml編寫器不生成它？

Answer 1

使用XmlWriterSettings.OmitXmlDeclaration。

不要忘記將XmlWriterSettings.ConformanceLevel設置爲ConformanceLevel.Fragment。

Answer 2

你也可以繼承XmlTextWriter並重寫WriteStartDocument()方法什麼都不做：

public class XmlFragmentWriter : XmlTextWriter 
{ 
    // Add whichever constructor(s) you need, e.g.: 
    public XmlFragmentWriter(Stream stream, Encoding encoding) : base(stream, encoding) 
    { 
    } 

    public override void WriteStartDocument() 
    { 
     // Do nothing (omit the declaration) 
    } 
} 

用法：

var stream = new MemoryStream(); 
var writer = new XmlFragmentWriter(stream, Encoding.UTF8); 
// Use the writer ... 

參考：這blog post斯科特Hanselman的。

Answer 3

你可以使用XmlWriter.Create()有：

new XmlWriterSettings { OmitXmlDeclaration = true, ConformanceLevel = ConformanceLevel.Fragment } 

    public static string FormatXml(string xml) 
    { 
     if (string.IsNullOrEmpty(xml)) 
      return string.Empty; 

     try 
     { 
      XmlDocument document = new XmlDocument(); 
      document.LoadXml(xml); 
      using (MemoryStream memoryStream = new MemoryStream()) 
      using (XmlWriter writer = XmlWriter.Create(memoryStream, new XmlWriterSettings { Encoding = Encoding.Unicode, OmitXmlDeclaration = true, ConformanceLevel = ConformanceLevel.Fragment, Indent = true, NewLineOnAttributes = false })) 
      { 
       document.WriteContentTo(writer); 
       writer.Flush(); 
       memoryStream.Flush(); 
       memoryStream.Position = 0; 
       using (StreamReader streamReader = new StreamReader(memoryStream)) 
       { 
        return streamReader.ReadToEnd(); 
       } 
      } 
     } 
     catch (XmlException ex) 
     { 
      return "Unformatted Xml version." + Environment.NewLine + ex.Message; 
     } 
     catch (Exception ex) 
     { 
      return "Unformatted Xml version." + Environment.NewLine + ex.Message; 
     } 
    }