如何使用没有声明元素的xml编写器创建xml

Question

我使用XmlWriter.Create()来获取编写器实例然后编写XML，但结果是<?xml version="1.0" encoding="utf-16" ?>，如何告诉我的xml编写器不生成它？

Answer 1

使用XmlWriterSettings.OmitXmlDeclaration。

不要忘记将XmlWriterSettings.ConformanceLevel设置为ConformanceLevel.Fragment。

Answer 2

您可以继承XmlTextWriter并覆盖WriteStartDocument()方法，不执行任何操作：

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 ...

参考：来自Scott Hanselman的blog post。

Answer 3

您可以将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; } } 用于：

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