如何在使用Xmlnclude后删除不需要的属性?

时间:2015-03-25 23:19:29

标签: c# xml-namespaces xmlserializer

我尝试序列化到以下XML:

...
<ManifestHeader>
    <Party Role="CHARGE">
        <f:Name>Name1</f:Name>
        ...
    </Party>
    <Party Role="SENDER">
        <Name>Name2</Name>
        ...
    </Party>
</ManifestHeader>
...

但是我得到了一些不需要的属性:

<ManifestHeader>
    <Party d4p1:type="PickupParty" Role="CHARGE" xmlns:d4p1="http://www.w3.org/2001/XMLSchema-instance">
        <f:Name>Name1</f:Name>
        ...

如何摆脱d4p1:typexmlns:d4p1属性?

我有一个抽象类AParty,有两个子类ChargePartySenderParty

在我的ManifestHeader课程中,我有:

    [XmlElement("Party")]
    public AParty[] Parties;

我使用XmlInclude如下:

[XmlInclude(typeof(PickupParty))]
[XmlInclude(typeof(SenderParty))]

在我的序列化器中,我使用自定义命名空间:

serialiser.Serialize(file, this, nameSpace);

有什么想法吗?


修改

我在发布问题之前检查了that question。首先我使用XmlSerializer而不是DataContractSerializer,其次我已成功为我的所有对象设置名称空间,除了包含在XmlInclude中。因此这个问题。

2 个答案:

答案 0 :(得分:3)

属性"{http://www.w3.org/2001/XMLSchema-instance}type"通常以前缀“xsi:type”出现,是多态元素显式断言其类型的标准方式。 XmlSerializer将其用于determine the type to deserialize - 因此在序列化期间将其写入以供日后使用。

在保持每个多态类型的相同元素名称的同时,没有简单的方法来抑制类型的输出。 (如果AParty的每个子类都有不同的元素名称,那将很容易,但你没有。)最好的选择是ManifestHeader实现IXmlSerializable。您没有完全指定ManifestHeader,因此请考虑以下示例:

[XmlRoot("ManifestHeader", Namespace = ManifestHeader.XmlNamespace)]
public class ManifestHeader : IXmlSerializable
{
    public const string XmlNamespace = "MyNamespace";

    public static XmlSerializerNamespaces GetXmlSerializerNamespaces()
    {
        var ns = new XmlSerializerNamespaces();
        ns.Add("", ManifestHeader.XmlNamespace);
        return ns;
    }

    // Some example properties

    public string AProperty { get; set; }

    public string ZProperty { get; set; }

    // The list of parties.

    public AParty[] Parties { get; set; }

    #region IXmlSerializable Members

    XmlSchema IXmlSerializable.GetSchema()
    {
        return null;
    }

    void IXmlSerializable.ReadXml(XmlReader reader)
    {
        throw new NotImplementedException();
    }

    void IXmlSerializable.WriteXml(XmlWriter writer)
    {
        var ns = GetXmlSerializerNamespaces();
        writer.WriteElementString("ZProperty", ZProperty);
        foreach (var value in Parties)
        {
            XmlSerializationHelper.SerializeElementTo(value, "Party", ManifestHeader.XmlNamespace, writer, ns);
        }
        writer.WriteElementString("AProperty", AProperty);
    }
    #endregion
}

public abstract class AParty
{
    [XmlAttribute]
    public abstract string Role { get; set; } // Returns a constant string; setter does nothing.
}

这会手动序列化ManifestHeader(如果有)的属性,循环遍历Party数组的元素并序列化每个元素,并用"Party"替换它们的元素名称。

它使用以下辅助方法。请注意,如果要使用XmlSerializer(Type, XmlRootAttribute)构造函数覆盖根元素名称,则一个必须 cache the serializer in a hash table to avoid a horrible memory leak

public static class XmlSerializationHelper
{
    public static void SerializeElementTo<T>(T value, string elementName, string elementNamespace, XmlWriter writer, XmlSerializerNamespaces ns)
    {
        var serializer = XmlSerializerRootAttributeCache.DemandSerializer(value.GetType(), elementName, elementNamespace);
        serializer.Serialize(writer, value, ns);
    }

    public static string GetXml<T>(this T obj)
    {
        return GetXml(obj, false);
    }

    public static string GetXml<T>(this T obj, bool omitNamespace)
    {
        return GetXml(obj, new XmlSerializer(obj.GetType()), omitNamespace);
    }

    public static string GetXml<T>(this T obj, XmlSerializer serializer)
    {
        return GetXml(obj, serializer, false);
    }

    public static string GetXml<T>(T obj, XmlSerializer serializer, bool omitStandardNamespaces)
    {
        XmlSerializerNamespaces ns = null;
        if (omitStandardNamespaces)
        {
            ns = new XmlSerializerNamespaces();
            ns.Add("", ""); // Disable the xmlns:xsi and xmlns:xsd lines.
        }
        return GetXml(obj, serializer, ns);
    }

    public static string GetXml<T>(T obj, XmlSerializer serializer, XmlSerializerNamespaces ns)
    {
        using (var textWriter = new StringWriter())
        {
            var settings = new XmlWriterSettings() { Indent = true, IndentChars = "    " }; // For cosmetic purposes.
            using (var xmlWriter = XmlWriter.Create(textWriter, settings))
                serializer.Serialize(xmlWriter, obj, ns);
            return textWriter.ToString();
        }
    }

    public static string GetXml<T>(this T obj, XmlSerializerNamespaces ns)
    {
        return GetXml(obj, new XmlSerializer(obj.GetType()), ns);
    }
}

public static class XmlSerializerRootAttributeCache
{
    readonly static Dictionary<Tuple<Type, string, string>, XmlSerializer> cache;
    readonly static object padlock = new object();

    static XmlSerializerRootAttributeCache()
    {
        cache = new Dictionary<Tuple<Type, string, string>, XmlSerializer>();
    }

    static XmlSerializer CreateSerializer(Type rootType, string rootName, string rootNamespace)
    {
        return new XmlSerializer(rootType, new XmlRootAttribute { ElementName = rootName, Namespace = rootNamespace });
    }

    public static XmlSerializer DemandSerializer(Type rootType, string rootName, string rootNamespace)
    {
        var key = Tuple.Create(rootType, rootName, rootNamespace);
        lock (padlock)
        {
            XmlSerializer serializer;
            if (!cache.TryGetValue(key, out serializer))
                serializer = cache[key] = CreateSerializer(rootType, rootName, rootNamespace);
            return serializer;
        }
    }
}

这是一个简单的测试用例:

[XmlRoot("ChargeParty", Namespace = ManifestHeader.XmlNamespace)]
[XmlType("ChargeParty", Namespace = ManifestHeader.XmlNamespace)]
public sealed class ChargeParty : AParty
{
    [XmlAttribute]
    public override string Role
    {
        get
        {
            return "CHARGE";
        }
        set
        {
        }
    }

    public bool IsCharging { get; set; }
}

[XmlRoot("SenderParty", Namespace = ManifestHeader.XmlNamespace)]
[XmlType("SenderParty", Namespace = ManifestHeader.XmlNamespace)]
public sealed class SenderParty : AParty
{
    [XmlAttribute]
    public override string Role
    {
        get
        {
            return "SENDER";
        }
        set
        {
        }
    }

    public string SenderName { get; set; }
}

public static class TestClass
{
    public static void Test()
    {
        var manifest = new ManifestHeader
        {
            AProperty = "A property",
            ZProperty = "Z Property",
            Parties = new AParty[] { new SenderParty { SenderName = "Sender Name" }, new ChargeParty { IsCharging = true }, new SenderParty { SenderName = "Another Sender Name" }, new SenderParty { SenderName = "Yet Another Sender Name" }, new ChargeParty { IsCharging = false } }
        };
        var xml = manifest.GetXml(ManifestHeader.GetXmlSerializerNamespaces());
        Debug.WriteLine(xml);
    }
}

产生:

<ManifestHeader xmlns="MyNamespace">
    <ZProperty>Z Property</ZProperty>
    <Party Role="SENDER">
        <SenderName>Sender Name</SenderName>
    </Party>
    <Party Role="CHARGE">
        <IsCharging>true</IsCharging>
    </Party>
    <Party Role="SENDER">
        <SenderName>Another Sender Name</SenderName>
    </Party>
    <Party Role="SENDER">
        <SenderName>Yet Another Sender Name</SenderName>
    </Party>
    <Party Role="CHARGE">
        <IsCharging>true</IsCharging>
    </Party>
    <AProperty>A property</AProperty>
</ManifestHeader>

答案 1 :(得分:1)

这是一种解决方法,而不是真正的解决方案。

我没有使用基类和子类,只使用了一个大类,这避免了XmlInclude的需要,从而避免了不需要的属性(d4p1:typexmlns:d4p1)。< / p>

我使用的单个大类基本上具有前面子类的所有属性。根据类的角色,仅使用属性的子集。

这非常难看,所以如果有人有一个合适的解决方案,那就是吝啬!