如何在使用asp.net核心时删除xml根命名空间

Question

在使用asp.net核心和XmlDataContractSerializerOutputFormatter格式化响应的情况下，如何删除根xml名称空间。

所有返回的xml文档都具有以下格式

<?xml version="1.0" encoding="utf-8"?>
   <response xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
      some other stuff
   </response>

我需要删除xmlns:i="http://www.w3.org/2001/XMLSchema-instance“部分。

Answer 1

请尝试以下代码：

xmlDoc.Load(@"FILE_PATH");
XmlNodeList header_el = xmlDoc.GetElementsByTagName("response");

foreach (XmlNode child in header_el)
{
  if (child.Attributes[0] != null)
  child.Attributes.Remove(child.Attributes[0]);
}
Console.WriteLine(xmlDoc.OuterXml);

此代码的输出为：

<?xml version="1.0" encoding="utf-8"?><response>
   some other stuff
</response>

Answer 2

最后，我扩展了现有的XmlDataContractSerializerOutputFormatter，使用创建xmlwriter对象的方法，并将其包装在适配器中以编辑功能，因为由于框架所表示的响应对象的结构，编辑响应实际上并不是一个实际可行的解决方案。

首先是格式化程序

public class CustomDataContractOutputFormatter : XmlDataContractSerializerOutputFormatter
{
    public CustomDataContractOutputFormatter() : base(){}
    public CustomDataContractOutputFormatter(XmlWriterSettings set) : base(set){}
    public override XmlWriter CreateXmlWriter(TextWriter writer, XmlWriterSettings xmlWriterSettings)
    {
        var bas = base.CreateXmlWriter(writer, xmlWriterSettings);
        var ret = new XmlWriterNoNamespace();
        ret.AdaptedWriter = bas;
        return ret;
    }
}

然后是基本适配器(其中一部分)

public class XmlWriterAdapter : XmlWriter
{
    XmlWriter _adaptedWriter;
    public XmlWriterAdapter():base(){}
    public XmlWriter AdaptedWriter 
    {
        get
        {
            return _adaptedWriter;
        } 
        set
        {
            this._adaptedWriter = value;
        }
    }
    public override WriteState WriteState { get{return _adaptedWriter.WriteState;} }
    public override void Flush()
    {
        _adaptedWriter.Flush();
    }
    public override string LookupPrefix(string ns)
    {
        return _adaptedWriter.LookupPrefix(ns);
    }
}

最后，使用hack来禁止名称空间的写入的特定适配器

public class XmlWriterNoNamespace : XmlWriterAdapter
{
    bool _skipAttribute;
    public XmlWriterNoNamespace():base(){}
    public override void WriteEndAttribute()
    {
        if(_skipAttribute)
        {
            _skipAttribute = false;
            return;
        }
        base.WriteEndAttribute();
    }
    public override void WriteStartAttribute(string prefix, string localName, string ns)
    {
        if(prefix.Equals("xmlns"))
        {
            _skipAttribute = true;
            return;
        }
        base.WriteStartAttribute(prefix, localName, ns);
    }
    public override void WriteString(string text)
    {
        if(_skipAttribute)
            return;
        base.WriteString(text);
    }
}