如何:使用 XSD 进行验证 (LINQ to XML)

更新:November 2007

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

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

本示例生成以下输出:

Validating doc1
doc1 validated

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

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 (LINQ to XML) 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,订单将指向不存在的客户,因此该 XML 文档不再有效。

本示例使用下面的 XML 文档:示例 XML 文件:客户和订单 (LINQ to XML).

本示例使用下面的 XSD 架构:示例 XSD 文件:客户和订单.

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 will not 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 will not 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

此示例产生以下输出:

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

请参见

概念

创建 XML 树

参考

Validate