停止DataContractSerializer放入命名空间?

...
XmlSerializer s = new XmlSerializer(objectToSerialize.GetType());
XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
ns.Add("","");
s.Serialize(xmlWriter, objectToSerialize, ns);

这是两个答案中的第二个。

如果您想在序列化过程中任意地从文档中剥离所有名称空间,可以通过实现自己的XmlWriter来实现。

最简单的方法是从XmlTextWriter派生并重写发出名称空间的StartElement方法。当发出任何元素(包括根元素)时,XmlSerializer将调用StartElement方法。通过覆盖每个元素的名称空间,并用空字符串替换它,您已经从输出中剥离了名称空间。

public class NoNamespaceXmlWriter : XmlTextWriter
{
    //Provide as many contructors as you need
    public NoNamespaceXmlWriter(System.IO.TextWriter output)
        : base(output) { Formatting= System.Xml.Formatting.Indented;}

    public override void WriteStartDocument () { }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        base.WriteStartElement("", localName, "");
    }
}

假设这是一种类型:

// explicitly specify a namespace for this type,
// to be used during XML serialization.
[XmlRoot(Namespace="urn:Abracadabra")]
public class MyTypeWithNamespaces
{
    // private fields backing the properties
    private int _Epoch;
    private string _Label;

    // explicitly define a distinct namespace for this element
    [XmlElement(Namespace="urn:Whoohoo")]
    public string Label
    {
        set {  _Label= value; } 
        get { return _Label; } 
    }

    // this property will be implicitly serialized to XML using the
    // member name for the element name, and inheriting the namespace from
    // the type.
    public int Epoch
    {
        set {  _Epoch= value; } 
        get { return _Epoch; } 
    }
}

下面是在序列化过程中如何使用这样的东西:

        var o2= new MyTypeWithNamespaces { ..intializers.. };
        var builder = new System.Text.StringBuilder();
        using ( XmlWriter writer = new NoNamespaceXmlWriter(new System.IO.StringWriter(builder)))
        {
            s2.Serialize(writer, o2, ns2);
        }            
        Console.WriteLine("{0}",builder.ToString());

但是XmlTextWriter有点坏了。根据 reference doc

• 属性和元素名称中的字符无效。

• 编码时,XmlTextWriter不会 角色实体。

• 重复属性。

• DOCTYPE public中的字符 标识符或系统标识符。

XmlTextWriter的这些问题从.NETFramework的v1.1开始就一直存在,而且为了向后兼容,这些问题将一直存在。如果您不担心这些问题,那么请务必使用XmlTextWriter。但大多数人希望更可靠一点。

XmlWriter 以及它的24种方法。

例如:

public class XmlWriterWrapper : XmlWriter
{
    protected XmlWriter writer;

    public XmlWriterWrapper(XmlWriter baseWriter)
    {
        this.Writer = baseWriter;
    }

    public override void Close()
    {
        this.writer.Close();
    }

    protected override void Dispose(bool disposing)
    {
        ((IDisposable) this.writer).Dispose();
    }

    public override void Flush()
    {
        this.writer.Flush();
    }

    public override string LookupPrefix(string ns)
    {
        return this.writer.LookupPrefix(ns);
    }

    public override void WriteBase64(byte[] buffer, int index, int count)
    {
        this.writer.WriteBase64(buffer, index, count);
    }

    public override void WriteCData(string text)
    {
        this.writer.WriteCData(text);
    }

    public override void WriteCharEntity(char ch)
    {
        this.writer.WriteCharEntity(ch);
    }

    public override void WriteChars(char[] buffer, int index, int count)
    {
        this.writer.WriteChars(buffer, index, count);
    }

    public override void WriteComment(string text)
    {
        this.writer.WriteComment(text);
    }

    public override void WriteDocType(string name, string pubid, string sysid, string subset)
    {
        this.writer.WriteDocType(name, pubid, sysid, subset);
    }

    public override void WriteEndAttribute()
    {
        this.writer.WriteEndAttribute();
    }

    public override void WriteEndDocument()
    {
        this.writer.WriteEndDocument();
    }

    public override void WriteEndElement()
    {
        this.writer.WriteEndElement();
    }

    public override void WriteEntityRef(string name)
    {
        this.writer.WriteEntityRef(name);
    }

    public override void WriteFullEndElement()
    {
        this.writer.WriteFullEndElement();
    }

    public override void WriteProcessingInstruction(string name, string text)
    {
        this.writer.WriteProcessingInstruction(name, text);
    }

    public override void WriteRaw(string data)
    {
        this.writer.WriteRaw(data);
    }

    public override void WriteRaw(char[] buffer, int index, int count)
    {
        this.writer.WriteRaw(buffer, index, count);
    }

    public override void WriteStartAttribute(string prefix, string localName, string ns)
    {
        this.writer.WriteStartAttribute(prefix, localName, ns);
    }

    public override void WriteStartDocument()
    {
        this.writer.WriteStartDocument();
    }

    public override void WriteStartDocument(bool standalone)
    {
        this.writer.WriteStartDocument(standalone);
    }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        this.writer.WriteStartElement(prefix, localName, ns);
    }

    public override void WriteString(string text)
    {
        this.writer.WriteString(text);
    }

    public override void WriteSurrogateCharEntity(char lowChar, char highChar)
    {
        this.writer.WriteSurrogateCharEntity(lowChar, highChar);
    }

    public override void WriteValue(bool value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(DateTime value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(decimal value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(double value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(int value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(long value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(object value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(float value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(string value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteWhitespace(string ws)
    {
        this.writer.WriteWhitespace(ws);
    }


    public override XmlWriterSettings Settings
    {
        get
        {
            return this.writer.Settings;
        }
    }

    protected XmlWriter Writer
    {
        get
        {
            return this.writer;
        }
        set
        {
            this.writer = value;
        }
    }

    public override System.Xml.WriteState WriteState
    {
        get
        {
            return this.writer.WriteState;
        }
    }

    public override string XmlLang
    {
        get
        {
            return this.writer.XmlLang;
        }
    }

    public override System.Xml.XmlSpace XmlSpace
    {
        get
        {
            return this.writer.XmlSpace;
        }
    }        
}

然后,像前面一样,提供一个重写StartElement方法的派生类:

public class NamespaceSupressingXmlWriter : XmlWriterWrapper
{
    //Provide as many contructors as you need
    public NamespaceSupressingXmlWriter(System.IO.TextWriter output)
        : base(XmlWriter.Create(output)) { }

    public NamespaceSupressingXmlWriter(XmlWriter output)
        : base(XmlWriter.Create(output)) { }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        base.WriteStartElement("", localName, "");
    }
}

然后像这样使用这个书写器:

        var o2= new MyTypeWithNamespaces { ..intializers.. };
        var builder = new System.Text.StringBuilder();
        var settings = new XmlWriterSettings { OmitXmlDeclaration = true, Indent= true };
        using ( XmlWriter innerWriter = XmlWriter.Create(builder, settings))
            using ( XmlWriter writer = new NamespaceSupressingXmlWriter(innerWriter))
            {
                s2.Serialize(writer, o2, ns2);
            }            
        Console.WriteLine("{0}",builder.ToString());

Oleg Tkachenko .

在阅读了微软的文档和一些在线解决方案之后,我发现了这个问题的解决方案。它与内置 XmlSerializer IXmlSerialiazble .

也就是说,我会用同样的方法 MyTypeWithNamespaces 到目前为止,这个问题的答案中使用的XML示例。

[XmlRoot("MyTypeWithNamespaces", Namespace="urn:Abracadabra", IsNullable=false)]
public class MyTypeWithNamespaces
{
    // As noted below, per Microsoft's documentation, if the class exposes a public
    // member of type XmlSerializerNamespaces decorated with the 
    // XmlNamespacesDeclarationAttribute, then the XmlSerializer will utilize those
    // namespaces during serialization.
    public MyTypeWithNamespaces( )
    {
        this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
            // Don't do this!! Microsoft's documentation explicitly says it's not supported.
            // It doesn't throw any exceptions, but in my testing, it didn't always work.

            // new XmlQualifiedName(string.Empty, string.Empty),  // And don't do this:
            // new XmlQualifiedName("", "")

            // DO THIS:
            new XmlQualifiedName(string.Empty, "urn:Abracadabra") // Default Namespace
            // Add any other namespaces, with prefixes, here.
        });
    }

    // If you have other constructors, make sure to call the default constructor.
    public MyTypeWithNamespaces(string label, int epoch) : this( )
    {
        this._label = label;
        this._epoch = epoch;
    }

    // An element with a declared namespace different than the namespace
    // of the enclosing type.
    [XmlElement(Namespace="urn:Whoohoo")]
    public string Label
    {
        get { return this._label; }
        set { this._label = value; }
    }
    private string _label;

    // An element whose tag will be the same name as the property name.
    // Also, this element will inherit the namespace of the enclosing type.
    public int Epoch
    {
        get { return this._epoch; }
        set { this._epoch = value; }
    }
    private int _epoch;

    // Per Microsoft's documentation, you can add some public member that
    // returns a XmlSerializerNamespaces object. They use a public field,
    // but that's sloppy. So I'll use a private backed-field with a public
    // getter property. Also, per the documentation, for this to work with
    // the XmlSerializer, decorate it with the XmlNamespaceDeclarations
    // attribute.
    [XmlNamespaceDeclarations]
    public XmlSerializerNamespaces Namespaces
    {
        get { return this._namespaces; }
    }
    private XmlSerializerNamespaces _namespaces;
}

这就是这门课的全部内容。现在,有些人反对 XmlSerializerNamespaces

现在,当要序列化该类时,您将使用以下代码:

MyTypeWithNamespaces myType = new MyTypeWithNamespaces("myLabel", 42);

/******
   OK, I just figured I could do this to make the code shorter, so I commented out the
   below and replaced it with what follows:

// You have to use this constructor in order for the root element to have the right namespaces.
// If you need to do custom serialization of inner objects, you can use a shortened constructor.
XmlSerializer xs = new XmlSerializer(typeof(MyTypeWithNamespaces), new XmlAttributeOverrides(),
    new Type[]{}, new XmlRootAttribute("MyTypeWithNamespaces"), "urn:Abracadabra");

******/
XmlSerializer xs = new XmlSerializer(typeof(MyTypeWithNamespaces),
    new XmlRootAttribute("MyTypeWithNamespaces") { Namespace="urn:Abracadabra" });

// I'll use a MemoryStream as my backing store.
MemoryStream ms = new MemoryStream();

// This is extra! If you want to change the settings for the XmlSerializer, you have to create
// a separate XmlWriterSettings object and use the XmlTextWriter.Create(...) factory method.
// So, in this case, I want to omit the XML declaration.
XmlWriterSettings xws = new XmlWriterSettings();
xws.OmitXmlDeclaration = true;
xws.Encoding = Encoding.UTF8; // This is probably the default
// You could use the XmlWriterSetting to set indenting and new line options, but the
// XmlTextWriter class has a much easier method to accomplish that.

// The factory method returns a XmlWriter, not a XmlTextWriter, so cast it.
XmlTextWriter xtw = (XmlTextWriter)XmlTextWriter.Create(ms, xws);
// Then we can set our indenting options (this is, of course, optional).
xtw.Formatting = Formatting.Indented;

// Now serialize our object.
xs.Serialize(xtw, myType, myType.Namespaces);

完成此操作后,应获得以下输出:

<MyTypeWithNamespaces>
    <Label xmlns="urn:Whoohoo">myLabel</Label>
    <Epoch>42</Epoch>
</MyTypeWithNamespaces>

我在最近的一个项目中成功地使用了这个方法,该项目有一个很深的类层次结构,这些类被序列化为XML以用于web服务调用。微软的文档并不是很清楚如何处理公共访问 XmlSerializerNamespaces IXmlSerializable .

xsi 和 xsd XmlSerializer .

更新:我只是想确保我回答了OP关于删除所有名称空间的问题。我上面的代码将用于此;让我演示如何。现在,在上面的示例中,您真的无法摆脱所有名称空间(因为有两个名称空间正在使用)。在XML文档的某个地方,您需要 xmlns="urn:Abracadabra" xmlns:w="urn:Whoohoo . 如果示例中的类是较大文档的一部分,则必须为其中一个(或两者)声明命名空间上方的某处 Abracadbra 和 Whoohoo Abracadabra 是defalt命名空间。我可以在我的房间里 MyTypeWithNamespaces 类为 屋虎

public MyTypeWithNamespaces
{
    this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
        new XmlQualifiedName(string.Empty, "urn:Abracadabra"), // Default Namespace
        new XmlQualifiedName("w", "urn:Whoohoo")
    });
}

现在,在我的类定义中,我指出 <Label/> "urn:Whoohoo"

<MyTypeWithNamespaces xmlns:w="urn:Whoohoo">
    <w:Label>myLabel</w:Label>
    <Epoch>42</Epoch>
</MyTypeWithNamespaces>

因为 <Label> 南印第安湖 和 xsd公司 名称空间。

XmlSerializer sr = new XmlSerializer(objectToSerialize.GetType());
TextWriter xmlWriter = new StreamWriter(filename);
XmlSerializerNamespaces namespaces = new XmlSerializerNamespaces();
namespaces.Add(string.Empty, string.Empty);
sr.Serialize(xmlWriter, objectToSerialize, namespaces);

如果您希望对名称空间进行良好的控制—例如,如果您希望省略其中的一些名称空间而不是其他名称空间,或者如果您希望用另一个名称空间替换一个名称空间,那么可以使用 XmlAttributeOverrides .

假设您有以下类型定义:

// explicitly specify a namespace for this type,
// to be used during XML serialization.
[XmlRoot(Namespace="urn:Abracadabra")]
public class MyTypeWithNamespaces
{
    // private fields backing the properties
    private int _Epoch;
    private string _Label;

    // explicitly define a distinct namespace for this element
    [XmlElement(Namespace="urn:Whoohoo")]
    public string Label
    {
        set {  _Label= value; } 
        get { return _Label; } 
    }

    // this property will be implicitly serialized to XML using the
    // member name for the element name, and inheriting the namespace from
    // the type.
    public int Epoch
    {
        set {  _Epoch= value; } 
        get { return _Epoch; } 
    }
}

        var o2= new MyTypeWithNamespaces() { ..initializers...};
        ns.Add( "", "urn:Abracadabra" );
        XmlSerializer s2 = new XmlSerializer(typeof(MyTypeWithNamespaces));
        s2.Serialize(System.Console.Out, o2, ns);

您将得到如下XML:

<MyTypeWithNamespaces xmlns="urn:Abracadabra">
  <Label xmlns="urn:Whoohoo">Cimsswybclaeqjh</Label>
  <Epoch>97</Epoch>
</MyTypeWithNamespaces>

注意,根元素上有一个默认名称空间,而“Label”元素上也有一个不同的名称空间。在上面的代码中,这些名称空间是由修饰类型的属性指定的。

NET中的Xml序列化框架包括显式 覆盖

        // instantiate the container for all attribute overrides
        XmlAttributeOverrides xOver = new XmlAttributeOverrides();

        // define a set of XML attributes to apply to the root element
        XmlAttributes xAttrs1 = new XmlAttributes();

        // define an XmlRoot element (as if [XmlRoot] had decorated the type)
        // The namespace in the attribute override is the empty string. 
        XmlRootAttribute xRoot = new XmlRootAttribute() { Namespace = ""};

        // add that XmlRoot element to the container of attributes
        xAttrs1.XmlRoot= xRoot;

        // add that bunch of attributes to the container holding all overrides
        xOver.Add(typeof(MyTypeWithNamespaces), xAttrs1);

        // create another set of XML Attributes
        XmlAttributes xAttrs2 = new XmlAttributes();

        // define an XmlElement attribute, for a type of "String", with no namespace
        var xElt = new XmlElementAttribute(typeof(String)) { Namespace = ""};

        // add that XmlElement attribute to the 2nd bunch of attributes
        xAttrs2.XmlElements.Add(xElt);

        // add that bunch of attributes to the container for the type, and
        // specifically apply that bunch to the "Label" property on the type.
        xOver.Add(typeof(MyTypeWithNamespaces), "Label", xAttrs2);

        // instantiate a serializer with the overrides 
        XmlSerializer s3 = new XmlSerializer(typeof(MyTypeWithNamespaces), xOver);

        // serialize
        s3.Serialize(System.Console.Out, o2, ns2);

结果是这样的;

<MyTypeWithNamespaces>
  <Label>Cimsswybclaeqjh</Label>
  <Epoch>97</Epoch>
</MyTypeWithNamespaces>

你已经剥离了名称空间。

一个合乎逻辑的问题是, 在序列化过程中,是否可以从任意类型中剥离所有名称空间,而不必进行显式重写? 答案是肯定的,如何做到这一点是在我的下一个回应。