xsi:type属性弄乱了C#XML反序列化 [英] xsi:type attribute messing up C# XML deserialization
问题描述
我使用XSD.exe根据XML模式(.xsd文件)自动生成C#对象.我正在反序列化OpenCover输出，但是部分类之一没有正确生成.
I used XSD.exe to automatically generate C# objects based on the XML schemas (.xsd files). I'm deserializing OpenCover output, but one of the partial classes didn't get generated correctly.
以下是引起异常的行:
<MethodPoint xsi:type="SequencePoint" vc="0" uspid="1" ordinal="0" offset="0" sl="19" sc="9" el="19" ec="10" bec="0" bev="0" fileid="1" />
这是MethodPoint类的简化版本:
Here's a shortened version of the MethodPoint class:
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.33440")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)]
public partial class CoverageSessionModulesModuleClassesClassMethodsMethodMethodPoint {
private string vcField;
private string uspidField;
private string ordinalField;
private string offsetField;
private string slField;
private string scField;
private string elField;
private string ecField;
private string becField;
private string bevField;
private string fileidField;
}
现在我已经遍历了很多.xml文件，但是OpenCover输出文件是唯一在属性内包含冒号的文件. MethodPoint对象也是唯一一个在属性中包含冒号的对象.如您所见，该类不包含xsi:type属性，并且我知道，由于冒号，仅添加它是行不通的.您如何处理xsi前缀?
Now I've been going through a lot of .xml files, but the OpenCover output files are the only ones that contain a colon inside an attribute. The MethodPoint object is also the only object that contains a colon in an attribute. As you can see, the class does not contain the xsi:type attribute, and I know that simply adding it won't work because of the colon. How do you deal with the xsi prefix?
这是从OpenCover XML文件之一生成的原始.xsd
Here is the raw .xsd generated from one of the OpenCover XML files
<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="CoverageSession" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="Summary">
<xs:complexType>
<xs:attribute name="numSequencePoints" type="xs:string" />
<xs:attribute name="visitedSequencePoints" type="xs:string" />
<xs:attribute name="numBranchPoints" type="xs:string" />
<xs:attribute name="visitedBranchPoints" type="xs:string" />
<xs:attribute name="sequenceCoverage" type="xs:string" />
<xs:attribute name="branchCoverage" type="xs:string" />
<xs:attribute name="maxCyclomaticComplexity" type="xs:string" />
<xs:attribute name="minCyclomaticComplexity" type="xs:string" />
<xs:attribute name="visitedClasses" type="xs:string" />
<xs:attribute name="numClasses" type="xs:string" />
<xs:attribute name="visitedMethods" type="xs:string" />
<xs:attribute name="numMethods" type="xs:string" />
</xs:complexType>
</xs:element>
<xs:element name="CoverageSession" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element ref="Summary" />
<xs:element name="Modules">
<xs:complexType>
<xs:sequence>
<xs:element name="Module" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="FullName" type="xs:string" minOccurs="0" msdata:Ordinal="1" />
<xs:element name="ModuleName" type="xs:string" minOccurs="0" msdata:Ordinal="2" />
<xs:element ref="Summary" minOccurs="0" maxOccurs="unbounded" />
<xs:element name="Files" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="File" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="uid" type="xs:string" />
<xs:attribute name="fullPath" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="Classes" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="Class" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="FullName" type="xs:string" minOccurs="0" />
<xs:element ref="Summary" minOccurs="0" maxOccurs="unbounded" />
<xs:element name="Methods" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="Method" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="MetadataToken" type="xs:string" minOccurs="0" msdata:Ordinal="1" />
<xs:element name="Name" type="xs:string" minOccurs="0" msdata:Ordinal="2" />
<xs:element ref="Summary" minOccurs="0" maxOccurs="unbounded" />
<xs:element name="FileRef" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="uid" type="xs:string" />
</xs:complexType>
</xs:element>
<xs:element name="SequencePoints" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="SequencePoint" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="vc" type="xs:string" />
<xs:attribute name="uspid" type="xs:string" />
<xs:attribute name="ordinal" type="xs:string" />
<xs:attribute name="offset" type="xs:string" />
<xs:attribute name="sl" type="xs:string" />
<xs:attribute name="sc" type="xs:string" />
<xs:attribute name="el" type="xs:string" />
<xs:attribute name="ec" type="xs:string" />
<xs:attribute name="bec" type="xs:string" />
<xs:attribute name="bev" type="xs:string" />
<xs:attribute name="fileid" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="BranchPoints" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="BranchPoint" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="vc" type="xs:string" />
<xs:attribute name="uspid" type="xs:string" />
<xs:attribute name="ordinal" type="xs:string" />
<xs:attribute name="offset" type="xs:string" />
<xs:attribute name="sl" type="xs:string" />
<xs:attribute name="path" type="xs:string" />
<xs:attribute name="offsetend" type="xs:string" />
<xs:attribute name="fileid" type="xs:string" />
<xs:attribute name="offsetchain" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="MethodPoint" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="vc" type="xs:string" />
<xs:attribute name="uspid" type="xs:string" />
<xs:attribute name="ordinal" type="xs:string" />
<xs:attribute name="offset" type="xs:string" />
<xs:attribute name="sl" type="xs:string" />
<xs:attribute name="sc" type="xs:string" />
<xs:attribute name="el" type="xs:string" />
<xs:attribute name="ec" type="xs:string" />
<xs:attribute name="bec" type="xs:string" />
<xs:attribute name="bev" type="xs:string" />
<xs:attribute name="fileid" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="visited" type="xs:string" />
<xs:attribute name="cyclomaticComplexity" type="xs:string" />
<xs:attribute name="sequenceCoverage" type="xs:string" />
<xs:attribute name="branchCoverage" type="xs:string" />
<xs:attribute name="isConstructor" type="xs:string" />
<xs:attribute name="isStatic" type="xs:string" />
<xs:attribute name="isGetter" type="xs:string" />
<xs:attribute name="isSetter" type="xs:string" />
<xs:attribute name="skippedDueTo" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="skippedDueTo" type="xs:string" />
<xs:attribute name="hash" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
推荐答案
The short answer is that you need to manually add [XmlInclude(typeof(SequencePoint))] to your MethodPoint class:
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.33440")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)]
[XmlInclude(typeof(SequencePoint))]
public partial class CoverageSessionModulesModuleClassesClassMethodsMethodMethodPoint {
private string vcField;
private string uspidField;
private string ordinalField;
private string offsetField;
private string slField;
private string scField;
private string elField;
private string ecField;
private string becField;
private string bevField;
private string fileidField;
}
如果还没有从MethodPoint继承，您还需要使其从MethodPoint继承.
You also need to make SequencePoint inherit from MethodPoint if it does not already do so.
之所以需要这样做，是因为当您使用xsd.exe从XML样本生成XSD ，然后依次使用c#类时，显然不会向基类添加多态子类型属性.当属性xsi:type="SomePolymoirphicSubType"出现在XML中时，即使它看起来应该会自动键入.
You need to do this because, when you use xsd.exe to generate an XSD from an XML sample, and then c# classes in turn, it apparently doesn't add polymorphic subtype attributes to base types automatically when the attribute xsi:type="SomePolymoirphicSubType" appears in the XML, even though it seems it should.
说明如下. xsi:type属性(是{http://www.w3.org/2001/XMLSchema-instance}type的缩写)是 w3c标准属性允许元素明确声明其类型，例如当它是预期元素类型的多态子类型时. XmlSerializer 支持此属性，并将使用它来确定实际的要反序列化为这种多态类型的对象的类型.但是，需要使用XmlIncludeAttribute .因此，如果我创建以下类型层次结构:
The explanation is as follows. The xsi:type attribute, short for {http://www.w3.org/2001/XMLSchema-instance}type, is a w3c standard attribute that allows an element to explicitly assert its type, e.g. when it is a polymorphic subtype of the expected element type. XmlSerializer supports this attribute and will use it to determine the actual type of object to deserialize for such a polymorphic type. However, it requires to be informed in advance of all possible types using XmlIncludeAttribute. Thus, if I create the following type hierarchy:
[XmlInclude(typeof(SequencePoint))]
public class MethodPoint
{
}
public class SequencePoint : MethodPoint
{
}
并将其序列化如下:
var test = new SequencePoint();
var serializer = new XmlSerializer(typeof(MethodPoint));
var sb = new StringBuilder();
using (var stream = new StringWriter(sb))
serializer.Serialize(stream, test);
Console.WriteLine(sb);
我得到以下XML:
<MethodPoint
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xsi:type="SequencePoint" />
然后，如果我使用var serializer = new XmlSerializer(typeof(MethodPoint))反序列化它，则会得到一个SequencePoint，而不是它的基类.如果我使用xsd.exe为这些类生成模式，则会得到:
Then if I deserialize it using var serializer = new XmlSerializer(typeof(MethodPoint)), I get back a SequencePoint, not its base class. And if I use xsd.exe to generate a schema for these classes, I get:
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="MethodPoint" nillable="true" type="MethodPoint" />
<xs:complexType name="MethodPoint" />
<xs:complexType name="SequencePoint">
<xs:complexContent mixed="false">
<xs:extension base="MethodPoint" />
</xs:complexContent>
</xs:complexType>
<xs:element name="SequencePoint" nillable="true" type="SequencePoint" />
</xs:schema>
注意xs:extension吗?这就是XSD指示多态子类型的方式.然后，如果我向后运行xsd.exe以重新生成我的类，则会得到:
Notice the xs:extension? That's how the XSD indicates a polymorphic subtype. And then if I run xsd.exe backwards to regenerate my classes, I get:
[System.Xml.Serialization.XmlIncludeAttribute(typeof(SequencePoint))]
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.3038")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=true)]
public partial class MethodPoint {
}
/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.3038")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=true)]
public partial class SequencePoint : MethodPoint {
}
如您所见，XmlIncludeAttribute就在其中，生成的类与原始类相同.到目前为止，一切正常.
As you can see, the XmlIncludeAttribute is there and the resulting classes are equivalent to the originals. Everything is working perfectly so far.
但是，当从示例XML文件中推断XSD时，xsd.exe似乎并没有出现xsi:type属性的情况.例如，如果我根据上述琐碎的XML创建XSD，则结果为:
But, it seems that when inferring an XSD from a sample XML file, xsd.exe doesn't pick up on the presence of the xsi:type attribute. For instance, if I create an XSD from the trivial XML above, the result is:
<xs:schema id="MethodPoint" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="MethodPoint" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded" />
</xs:complexType>
</xs:element>
</xs:schema>
多态亚型完全缺失.从该XSD生成的类将无法反序列化该XML.
The polymorphic subtype is completely missing. Classes generated from this XSD will not be able to deserialize that XML.
因此，似乎使用xsd.exe从XML样本生成c#类不如从适当的XSD生成c#类可靠.具体来说，在XML文件中出现xsi:type的情况下，您将需要手动修复生成的类或生成的XSD，以实现所需的层次结构.这可能是限制，也可能是工具中的错误.
So it seems that generating c# classes from an XML sample with xsd.exe just isn't as reliable as generating them from a proper XSD. Specifically, in cases where xsi:type appears in the XML file, you will need to manually fix either the generated classes or the generated XSD to implement the required hierarchy. This may be either a limitation or a bug in the tool.
(限制/错误也将出现在 将XML粘贴为类 (内部使用xsd.exe.)
(The limitation/bug will also appear in Paste XML as Classes which uses xsd.exe internally.)
这篇关于xsi:type属性弄乱了C#XML反序列化的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
