将通用对象序列化为SOAP格式的流的扩展方法 [英] Extension method to serialize generic objects as a SOAP formatted stream

问题描述

我很难找出一种通用的扩展方法，该方法可以将给定对象序列化为 SOAP 格式.实际的实现看起来像这样:

I'm having a hard time trying to figure out a generic extension method that would serialize a given object as SOAP formatted. The actual implementation looks somewhat like this:

Foobar.cs

[Serializable, XmlRoot("foobar"), DataContract]
public class Foobar
{
    [XmlAttribute("foo"), DataMember]
    public string Foo { get; set; }

    [XmlAttribute("bar"), DataMember]
    public string Bar { get; set; }

    public Foobar() {}
}

Lipsum.cs

[Serializable, XmlRoot("lipsum"), XmlType("lipsum"), DataContract]
public class Lipsum
{
    private List<Foobar> lipsum = new List<Foobar>();

    [XmlElement("foobar"), DataMember]
    public List<Foobar> Lipsum { get { return lipsum; } }
}

}

Extensions.cs

public static void SerializeToSoap<T>(this Stream target, T source)
{
    XmlTypeMapping xmlTypeMapping = (new SoapReflectionImporter().ImportTypeMapping(typeof(T)));
    XmlSerializer xmlSerializer = new XmlSerializer(xmlTypeMapping);
    xmlSerializer.Serialize(target, source);
}

Program.cs

static void Main()
{
    Lipsum lipsum = new Lipsum();
    lipsum.Lipsum.Add(
        new Foobar()
        {
            Foo = "Lorem",
            Bar = "Ipsum"
        }
    );

    using (MemoryStream persistence = new MemoryStream())
    {
        persistence.SerializeToSoap<Lipsum>(lipsum);
        Console.WriteLine(Encoding.Default.GetString(persistence.ToArray()));
        Console.WriteLine(Environment.NewLine);
    }
}

EXCEPTION

System.InvalidOperationException: Token StartElement in state Epilog would result in an invalid XML document.
   at System.Xml.XmlTextWriter.AutoComplete(Token token)
   at System.Xml.XmlTextWriter.WriteStartElement(String prefix, String localName, String ns)
   at System.Xml.Serialization.XmlSerializationWriter.WriteStartElement(String name, String ns, Object o, Boolean writePrefixed, XmlSerializerNamespaces xmlns)
   at System.Xml.Serialization.XmlSerializationWriter.WriteArray(String name, String ns, Object o, Type type)
   at System.Xml.Serialization.XmlSerializationWriter.WriteReferencedElement(String name, String ns, Object o, Type ambientType)
   at System.Xml.Serialization.XmlSerializationWriter.WriteReferencedElements()
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.
   Write4_Lipsum(Object o)

另一方面， XML 和 JSON 序列化(分别使用 XmlSerializer 和 DataContractJsonSerializer )都可以正常工作具有以下预期结果:

On the other hand both XML and JSON serialization (using XmlSerializer and DataContractJsonSerializer respectively) is working fine with the following expected results:

<?xml version="1.0"?>
<lipsum xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <foobar foo="Lorem" bar="Ipsum" />
</lipsum>

{"Lipsum":[{"Foo":"Lorem","Bar":"Ipsum"}]}

我们将不胜感激任何建议.提前谢谢.

Any advice will be sincerely appreciated. Thanks much in advance.

更新

正如其中一位评论者所述，有一个 SoapFormatter 类，但鉴于我知道它不能处理通用类型，因此未包含该代码段.所以无论如何，这将是该方案的代码:

As one of the commenters remarked, there's a SoapFormatter class but given that I was aware it can't deal with generic types haven't included that snippet. So anyway this would be the code for that scenario:

public static void SerializeToSoap<T>(this Stream target, T source)
{
    SoapFormatter soapFormatter = new SoapFormatter();
    soapFormatter.Serialize(target, source);
}

哪个抛出以下异常:

Exception caught: Soap Serializer does not support serializing Generic Types : System.Collections.Generic.List`1[Foobar].

更新2

按照Merlyn Morgan-Graham给出的指导，我尝试使用非通用对象来填充 SoapFormatter ，因此在与 MemoryStream 进行了一些混和之后，我结束了:

Following the lead given by Merlyn Morgan-Graham I've been tried to feed the SoapFormatter with a non-generic object, so after a little juggling with MemoryStream I've ended up with this:

using (MemoryStream xmlStream = new MemoryStream())
{
    XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
    xmlSerializer.Serialize(xmlStream, lipsum);

    using (MemoryStream soapStream = new MemoryStream()) 
    {
        SoapFormatter soapFormatter = new SoapFormatter();
        soapFormatter.Serialize(soapStream, Encoding.Default.GetString(xmlStream.ToArray()));
        Console.WriteLine(Encoding.Default.GetString(soapStream.ToArray()));
        Console.WriteLine(Environment.NewLine);
    }
}

令人惊讶的是，除了字符实体之外，还输出了不错的SOAP消息:

Which surprisingly enough, character entities aside, outputs a decent SOAP message:

<SOAP-ENV:Envelope
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:clr="http://schemas.microsoft.com/soap/encoding/clr/1.0"
    SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
    <SOAP-ENV:Body>
        <SOAP-ENC:string id="ref-1">
            &#60;?xml version=&#34;1.0&#34;?&#62;&#60;lipsum
            xmlns:xsi=&#34;http://www.w3.org/2001/XMLSchema-instance&#34;
            xmlns:xsd=&#34;http://www.w3.org/2001/XMLSchema&#34;&#62;&#60;
            foobar foo=&#34;Lorem&#34; bar=&#34;Ipsum&#34;/&#62;&#60;/lipsum&#62;
        </SOAP-ENC:string>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

推荐答案

我(一半)通过将序列化包装到另一个元素中来解决了这个问题，例如本论坛帖子:

I (half) solved the problem by wrapping the serialization with another element, ala this forum post: http://forums.asp.net/p/1510998/3607468.aspx, and this blog post: http://sandblogaspnet.blogspot.com/2009/07/serialization-in-net-3.html

public static void SerializeToSoap<T>(this Stream target, T source)
{
    XmlTypeMapping xmlTypeMapping = (new SoapReflectionImporter().ImportTypeMapping(typeof(T)));
    XmlSerializer xmlSerializer = new XmlSerializer(xmlTypeMapping);
    using (var xmlWriter = new XmlTextWriter(target, Encoding.UTF8))
    {
        xmlWriter.WriteStartDocument();
        xmlWriter.WriteStartElement("root");
        xmlSerializer.Serialize(xmlWriter, source);
        xmlWriter.WriteFullEndElement();
    }
}

不过，该文档看起来确实很奇怪，并且不包含SOAP信封.诚然，我对SOAP知之甚少，所以也许您知道如何解决这些问题:)

The document looks really strange, though, and doesn't contain a SOAP Envelope. Admittedly I know very little about SOAP, so maybe you know how to solve those problems :)

查看 System.Web.Services.Protocols.SoapHttpClientProtocol 中的反射源，看起来好像使用了 SoapReflectionImporter 和 XmlSerializer ，但是SOAP信封和正文直接在序列化代码中生成.没有特殊的帮助者可以看到给用户.因此，您可能必须用自定义代码包装消息的那一部分.

Looking at reflected source in System.Web.Services.Protocols.SoapHttpClientProtocol, it looks like the SoapReflectionImporter and XmlSerializer are used, but the SOAP envelope and body are generated directly within the serialization code. No special helpers are exposed to the user. So you'll probably have to wrap that part of the message with custom code.

从好的方面来说，代码看起来很简单-只需使用正确的名称空间/属性编写正确的元素即可.

On the plus side, the code looks fairly simple - just write the correct elements with the proper namespaces/attributes.

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