XmlSchemaUnique Classe

Definição

Namespace:
System.Xml.Schema
Assembly:
System.Xml.dll
Assembly:
netstandard.dll

Representa o unique elemento do esquema XML, conforme especificado pelo W3C (World Wide Web Consortium). Essa classe pode ser usada para identificar uma restrição exclusiva entre um conjunto de elementos.

public ref class XmlSchemaUnique : System::Xml::Schema::XmlSchemaIdentityConstraint
public class XmlSchemaUnique : System.Xml.Schema.XmlSchemaIdentityConstraint
type XmlSchemaUnique = class
    inherit XmlSchemaIdentityConstraint
Public Class XmlSchemaUnique
Inherits XmlSchemaIdentityConstraint
Herança
Object
XmlSchemaObject
XmlSchemaAnnotated
XmlSchemaIdentityConstraint
XmlSchemaUnique

Exemplos

O exemplo a seguir mostra o uso da XmlSchemaUnique classe.

using System;
using System.Xml;
using System.Xml.Schema;

class XMLSchemaExamples
{
    public static void Main()
    {

        XmlSchema schema = new XmlSchema();

        // <xs:complexType name="customerOrderType">
        XmlSchemaComplexType customerOrderType = new XmlSchemaComplexType();
        customerOrderType.Name = "customerOrderType";

        // <xs:sequence>
        XmlSchemaSequence sequence1 = new XmlSchemaSequence();

        // <xs:element name="item" minOccurs="0" maxOccurs="unbounded">
        XmlSchemaElement item = new XmlSchemaElement();
        item.MinOccurs = 0;
        item.MaxOccursString = "unbounded";
        item.Name = "item";

        // <xs:complexType>
        XmlSchemaComplexType ct1 = new XmlSchemaComplexType();

        // <xs:attribute name="itemID" type="xs:string"/>
        XmlSchemaAttribute itemID = new XmlSchemaAttribute();
        itemID.Name = "itemID";
        itemID.SchemaTypeName = new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        // </xs:complexType>
        ct1.Attributes.Add(itemID);

        // </xs:element>
        item.SchemaType = ct1;

        // </xs:sequence>
        sequence1.Items.Add(item);
        customerOrderType.Particle = sequence1;

        // <xs:attribute name="CustomerID" type="xs:string"/>
        XmlSchemaAttribute CustomerID = new XmlSchemaAttribute();
        CustomerID.Name = "CustomerID";
        CustomerID.SchemaTypeName = new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        customerOrderType.Attributes.Add(CustomerID);

        // </xs:complexType>
        schema.Items.Add(customerOrderType);

        // <xs:element name="ordersByCustomer">
        XmlSchemaElement ordersByCustomer = new XmlSchemaElement();
        ordersByCustomer.Name = "ordersByCustomer";

        // <xs:complexType>
        XmlSchemaComplexType ct2 = new XmlSchemaComplexType();

        // <xs:sequence>
        XmlSchemaSequence sequence2 = new XmlSchemaSequence();

        // <xs:element name="customerOrders" type="customerOrderType" minOccurs="0" maxOccurs="unbounded" />
        XmlSchemaElement customerOrders = new XmlSchemaElement();
        customerOrders.MinOccurs = 0;
        customerOrders.MaxOccursString = "unbounded";
        customerOrders.Name = "customerOrders";
        customerOrders.SchemaTypeName = new XmlQualifiedName("customerOrderType", "");

        // </xs:sequence>
        sequence2.Items.Add(customerOrders);

        // </xs:complexType>
        ct2.Particle = sequence2;
        ordersByCustomer.SchemaType = ct2;

        // <xs:unique name="oneCustomerOrdersforEachCustomerID">
        XmlSchemaUnique element_unique = new XmlSchemaUnique();
        element_unique.Name = "oneCustomerOrdersforEachCustomerID";

        // <xs:selector xpath="customerOrders"/>
        element_unique.Selector = new XmlSchemaXPath();
        element_unique.Selector.XPath = "customerOrders";

        // <xs:field xpath="@customerID"/>
        XmlSchemaXPath field = new XmlSchemaXPath();
        field.XPath = "@customerID";

        // </xs:unique>
        element_unique.Fields.Add(field);
        ordersByCustomer.Constraints.Add(element_unique);

        // </xs:element>
        schema.Items.Add(ordersByCustomer);

        XmlSchemaSet schemaSet = new XmlSchemaSet();
        schemaSet.ValidationEventHandler += new ValidationEventHandler(ValidationCallbackOne);
        schemaSet.Add(schema);
        schemaSet.Compile();

        XmlSchema compiledSchema = null;

        foreach (XmlSchema schema1 in schemaSet.Schemas())
        {
            compiledSchema = schema1;
        }

        XmlNamespaceManager nsmgr = new XmlNamespaceManager(new NameTable());
        nsmgr.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema");
        compiledSchema.Write(Console.Out, nsmgr);
    }

    public static void ValidationCallbackOne(object sender, ValidationEventArgs args)
    {
        Console.WriteLine(args.Message);
    }
}

Imports System.Xml
Imports System.Xml.Schema

Class XMLSchemaExamples
    Public Shared Sub Main()

        Dim schema As New XmlSchema()

        ' <xs:complexType name="customerOrderType">
        Dim customerOrderType As New XmlSchemaComplexType()
        customerOrderType.Name = "customerOrderType"

        ' <xs:sequence>
        Dim sequence1 As New XmlSchemaSequence()

        ' <xs:element name="item" minOccurs="0" maxOccurs="unbounded">
        Dim item As New XmlSchemaElement()
        item.MinOccurs = 0
        item.MaxOccursString = "unbounded"
        item.Name = "item"

        ' <xs:complexType>
        Dim ct1 As New XmlSchemaComplexType()

        ' <xs:attribute name="itemID" type="xs:string"/>
        Dim itemID As New XmlSchemaAttribute()
        itemID.Name = "itemID"
        itemID.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        ' </xs:complexType>
        ct1.Attributes.Add(itemID)

        ' </xs:element>
        item.SchemaType = ct1

        ' </xs:sequence>
        sequence1.Items.Add(item)
        customerOrderType.Particle = sequence1

        ' <xs:attribute name="CustomerID" type="xs:string"/>
        Dim CustomerID As New XmlSchemaAttribute()
        CustomerID.Name = "CustomerID"
        CustomerID.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        customerOrderType.Attributes.Add(CustomerID)

        ' </xs:complexType>
        schema.Items.Add(customerOrderType)

        ' <xs:element name="ordersByCustomer">
        Dim ordersByCustomer As New XmlSchemaElement()
        ordersByCustomer.Name = "ordersByCustomer"

        ' <xs:complexType>
        Dim ct2 As New XmlSchemaComplexType()

        ' <xs:sequence>
        Dim sequence2 As New XmlSchemaSequence()

        ' <xs:element name="customerOrders" type="customerOrderType" minOccurs="0" maxOccurs="unbounded" />
        Dim customerOrders As New XmlSchemaElement()
        customerOrders.MinOccurs = 0
        customerOrders.MaxOccursString = "unbounded"
        customerOrders.Name = "customerOrders"
        customerOrders.SchemaTypeName = New XmlQualifiedName("customerOrderType", "")

        ' </xs:sequence>
        sequence2.Items.Add(customerOrders)

        ' </xs:complexType>
        ct2.Particle = sequence2
        ordersByCustomer.SchemaType = ct2

        ' <xs:unique name="oneCustomerOrdersforEachCustomerID">
        Dim element_unique As New XmlSchemaUnique()
        element_unique.Name = "oneCustomerOrdersforEachCustomerID"

        ' <xs:selector xpath="customerOrders"/>
        element_unique.Selector = New XmlSchemaXPath()
        element_unique.Selector.XPath = "customerOrders"

        ' <xs:field xpath="@customerID"/>
        Dim field As New XmlSchemaXPath()
        field.XPath = "@customerID"

        ' </xs:unique>
        element_unique.Fields.Add(field)
        ordersByCustomer.Constraints.Add(element_unique)

        ' </xs:element>
        schema.Items.Add(ordersByCustomer)

        Dim schemaSet As New XmlSchemaSet()
        AddHandler schemaSet.ValidationEventHandler, AddressOf ValidationCallbackOne

        schemaSet.Add(schema)
        schemaSet.Compile()

        Dim compiledSchema As XmlSchema = Nothing

        For Each schema1 As XmlSchema In schemaSet.Schemas()
            compiledSchema = schema1
        Next

        Dim nsmgr As New XmlNamespaceManager(New NameTable())
        nsmgr.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema")
        compiledSchema.Write(Console.Out, nsmgr)

    End Sub

    Public Shared Sub ValidationCallbackOne(ByVal sender As Object, ByVal args As ValidationEventArgs)
        Console.WriteLine(args.Message)
    End Sub
End Class

O arquivo XML a seguir é gerado para este exemplo de código.

<?xml version="1.0" encoding="IBM437"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:complexType name="customerOrderType">
        <xs:sequence>
            <xs:element name="item" minOccurs="0" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:attribute name="itemID" type="xs:string"/>
                </xs:complexType>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="CustomerID" type="xs:string"/>
    </xs:complexType>

    <xs:element name="ordersByCustomer">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="customerOrders" type="customerOrderType" minOccurs="0" maxOccurs="unbounded" />
            </xs:sequence>
        </xs:complexType>
        <xs:unique name="oneCustomerOrdersforEachCustomerID">
            <xs:selector xpath="customerOrders"/>
            <xs:field xpath="@customerID"/>
        </xs:unique>
    </xs:element>
</xs:schema>

Comentários

Especifica que um valor de atributo ou elemento (ou uma combinação de valores de atributo ou elemento) deve ser exclusivo dentro do escopo especificado. O nome da restrição deve ser exclusivo em um esquema.

Construtores

Nome Description
XmlSchemaUnique()

Inicializa uma nova instância da classe XmlSchemaUnique.

Propriedades

Nome Description
Annotation

Obtém ou define a annotation propriedade.

(Herdado de XmlSchemaAnnotated)
Fields

Obtém a coleção de campos que se aplicam como filhos para o seletor de expressão XPath (Linguagem de Caminho XML).

(Herdado de XmlSchemaIdentityConstraint)
Id

Obtém ou define a ID da cadeia de caracteres.

(Herdado de XmlSchemaAnnotated)
LineNumber

Obtém ou define o número de linha no arquivo ao qual o schema elemento se refere.

(Herdado de XmlSchemaObject)
LinePosition

Obtém ou define a posição da linha no arquivo ao qual o schema elemento se refere.

(Herdado de XmlSchemaObject)
Name

Obtém ou define o nome da restrição de identidade.

(Herdado de XmlSchemaIdentityConstraint)
Namespaces

Obtém ou define o XmlSerializerNamespaces que usar com esse objeto de esquema.

(Herdado de XmlSchemaObject)
Parent

Obtém ou define o pai deste XmlSchemaObject.

(Herdado de XmlSchemaObject)
QualifiedName

Obtém o nome qualificado da restrição de identidade, que contém o valor pós-compilação da QualifiedName propriedade.

(Herdado de XmlSchemaIdentityConstraint)
Selector

Obtém ou define o elemento de expressão selector XPath.

(Herdado de XmlSchemaIdentityConstraint)
SourceUri

Obtém ou define o local de origem do arquivo que carregou o esquema.

(Herdado de XmlSchemaObject)
UnhandledAttributes

Obtém ou define os atributos qualificados que não pertencem ao namespace de destino do esquema atual.

(Herdado de XmlSchemaAnnotated)

Métodos

Nome Description
Equals(Object)

Determina se o objeto especificado é igual ao objeto atual.

(Herdado de Object)
GetHashCode()

Serve como a função hash predefinida.

(Herdado de Object)
GetType()

Obtém o Type da instância atual.

(Herdado de Object)
MemberwiseClone()

Cria uma cópia superficial do Objectatual.

(Herdado de Object)
ToString()

Retorna uma cadeia de caracteres que representa o objeto atual.

(Herdado de Object)

Aplica-se a