如何使用 XSD 进行验证 (LINQ to XML)

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System.Xml.Schema 命名空间包含扩展方法，这些扩展方法可以简化针对 XML 架构定义语言 (XSD) 文件验证 XML 树的过程。 有关更多信息，请参见 Validate 方法文档。

示例：针对 XmlSchemaSet 验证 XDocument 对象

下面的示例创建一个 XmlSchemaSet，然后针对架构集验证两个 XDocument 对象。 其中一个文档有效，另一个文档无效。

string xsdMarkup =
    @"<xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema'>
       <xsd:element name='Root'>
        <xsd:complexType>
         <xsd:sequence>
          <xsd:element name='Child1' minOccurs='1' maxOccurs='1'/>
          <xsd:element name='Child2' minOccurs='1' maxOccurs='1'/>
         </xsd:sequence>
        </xsd:complexType>
       </xsd:element>
      </xsd:schema>";
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add("", XmlReader.Create(new StringReader(xsdMarkup)));

XDocument doc1 = new XDocument(
    new XElement("Root",
        new XElement("Child1", "content1"),
        new XElement("Child2", "content1")
    )
);

XDocument doc2 = new XDocument(
    new XElement("Root",
        new XElement("Child1", "content1"),
        new XElement("Child3", "content1")
    )
);

Console.WriteLine("Validating doc1");
bool errors = false;
doc1.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("doc1 {0}", errors ? "did not validate" : "validated");

Console.WriteLine();
Console.WriteLine("Validating doc2");
errors = false;
doc2.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("doc2 {0}", errors ? "did not validate" : "validated");

Dim errors As Boolean = False

Private Sub XSDErrors(ByVal o As Object, ByVal e As ValidationEventArgs)
    Console.WriteLine("{0}", e.Message)
    errors = True
End Sub

Sub Main()
    Dim xsdMarkup As XElement = _
        <xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema'>
            <xsd:element name='Root'>
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element name='Child1' minOccurs='1' maxOccurs='1'/>
                        <xsd:element name='Child2' minOccurs='1' maxOccurs='1'/>
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
        </xsd:schema>
    Dim schemas As XmlSchemaSet = New XmlSchemaSet()
    schemas.Add("", xsdMarkup.CreateReader)

    Dim doc1 As XDocument = _
        <?xml version='1.0'?>
        <Root>
            <Child1>content1</Child1>
            <Child2>content1</Child2>
        </Root>

    Dim doc2 As XDocument = _
        <?xml version='1.0'?>
        <Root>
            <Child1>content1</Child1>
            <Child3>content1</Child3>
        </Root>

    Console.WriteLine("Validating doc1")
    errors = False
    doc1.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("doc1 {0}", IIf(errors = True, "did not validate", "validated"))

    Console.WriteLine()
    Console.WriteLine("Validating doc2")
    errors = False
    doc2.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("doc2 {0}", IIf(errors = True, "did not validate", "validated"))
End Sub

该示例产生下面的输出：

Validating doc1
doc1 validated

Validating doc2
The element 'Root' has invalid child element 'Child3'. List of possible elements expected: 'Child2'.
doc2 did not validate

示例：针对文件中的架构从文件验证 XML 文档

下面的示例按照示例 XSD 文件：客户和订单中的架构验证示例 XML 文件：客户和订单中的 XML 文档是否有效。 然后修改源 XML 文档。 它更改第一个客户的 CustomerID 属性。 更改后，订单将引用一个不存在的客户，因此 XML 文档将不再有效。

XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add("", "CustomersOrders.xsd");

Console.WriteLine("Attempting to validate");
XDocument custOrdDoc = XDocument.Load("CustomersOrders.xml");
bool errors = false;
custOrdDoc.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("custOrdDoc {0}", errors ? "did not validate" : "validated");

Console.WriteLine();
// Modify the source document so that it won't validate.
custOrdDoc.Root.Element("Orders").Element("Order").Element("CustomerID").Value = "AAAAA";
Console.WriteLine("Attempting to validate after modification");
errors = false;
custOrdDoc.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("custOrdDoc {0}", errors ? "did not validate" : "validated");

Dim errors As Boolean = False

Private Sub XSDErrors(ByVal o As Object, ByVal e As ValidationEventArgs)
    Console.WriteLine("{0}", e.Message)
    errors = True
End Sub

Sub Main()
    Dim schemas As XmlSchemaSet = New XmlSchemaSet()
    schemas.Add("", "CustomersOrders.xsd")

    Console.WriteLine("Attempting to validate")
    Dim custOrdDoc As XDocument = XDocument.Load("CustomersOrders.xml")
    errors = False
    custOrdDoc.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("custOrdDoc {0}", IIf(errors, "did not validate", "validated"))

    Console.WriteLine()
    ' Modify the source document so that it won't validate.
    custOrdDoc.<Root>.<Orders>.<Order>.<CustomerID>(0).Value = "AAAAA"
    Console.WriteLine("Attempting to validate after modification")
    errors = False
    custOrdDoc.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("custOrdDoc {0}", IIf(errors, "did not validate", "validated"))
End Sub

该示例产生下面的输出：

Attempting to validate
custOrdDoc validated

Attempting to validate after modification
The key sequence 'AAAAA' in Keyref fails to refer to some key.
custOrdDoc did not validate

请参阅