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併入或匯入 XML 結構描述

更新: November 2007

XML 結構描述可包含 <xs:import />, <xs:include /> 及 <xs:redefine /> 項目。 這些結構描述項目會參考其他 XML 結構描述,其可用於補充併入或匯入它們之結構描述的結構。 XmlSchemaImportXmlSchemaIncludeXmlSchemaRedefine 類別會對應至結構描述物件模型 (SOM) API 中的這些項目。

併入或匯入 XML 結構描述

下列程式碼範例會為 建置 XML 結構描述 主題中建立的客戶結構描述補充位址結構描述。 為客戶結構描述補充位址結構描述,可讓位址型別在客戶結構描述中使用。

您可使用 <xs:include /> 或 <xs:import /> 項目加入位址結構描述,以按原樣使用位址結構描述的元件,或使用 <xs:redefine /> 項目,修改其中任何元件以滿足客戶結構描述需要。 因為位址結構描述與客戶結構描述的 targetNamespace 不同,所以會使用 <xs:import /> 項目及匯入語意。

程式碼範例使用下列步驟併入位址結構描述。

  1. 將客戶結構描述及位址結構描述加入至新的 XmlSchemaSet 物件,然後對它們進行編譯。 讀取或編譯結構描述時遇到的任何結構描述驗證警告及錯誤,都會由 ValidationEventHandler 委派處理。

  2. 透過重複處理 Schemas 屬性,從 XmlSchemaSet 中為客戶及位址結構描述擷取已編譯的 XmlSchema 物件。 因為已編譯結構描述,因此可存取後結構描述編譯資訊集 (PSCI) 屬性。

  3. 建立 XmlSchemaImport 物件、將 import 的 Namespace 屬性設為位址結構描述的命名空間、將 import 的 Schema 屬性設為位址結構描述的 XmlSchema 物件,並將 import 加入客戶結構描述的 Includes 屬性中。

  4. 使用 XmlSchemaSet 類別的 ReprocessCompile 方法,重新處理並編譯客戶結構描述之已修改的 XmlSchema 物件,並將其寫入主控台。

  5. 最後,使用客戶結構描述的 Includes 屬性,將匯入至客戶結構描述的所有結構描述遞迴寫入主控台。 Includes 屬性對所有加入至結構描述的 include、import 或 redefine 提供存取權。

下列是完整程式碼範例及寫入主控台的客戶與位址結構描述。

Imports System
Imports System.Xml
Imports System.Xml.Schema

Class XmlSchemaImportExample

    Shared Sub Main()
        ' Add the customer and address schemas to a new XmlSchemaSet and compile them.
        ' Any schema validation warnings and errors encountered reading or 
        ' compiling the schemas are handled by the ValidationEventHandler delegate.
        Dim schemaSet As XmlSchemaSet = New XmlSchemaSet()
        AddHandler schemaSet.ValidationEventHandler, AddressOf ValidationCallback
        schemaSet.Add("http://www.tempuri.org", "customer.xsd")
        schemaSet.Add("http://www.example.com/IPO", "address.xsd")
        schemaSet.Compile()

        ' Retrieve the compiled XmlSchema objects for the customer and
        ' address schema from the XmlSchemaSet by iterating over 
        ' the Schemas property.
        Dim customerSchema As XmlSchema = Nothing
        Dim addressSchema As XmlSchema = Nothing
        For Each schema As XmlSchema In schemaSet.Schemas()
            If schema.TargetNamespace = "http://www.tempuri.org" Then
                customerSchema = schema
            ElseIf schema.TargetNamespace = "http://www.example.com/IPO" Then
                addressSchema = schema
            End If
        Next

        ' Create an XmlSchemaImport object, set the Namespace property
        ' to the namespace of the address schema, the Schema property 
        ' to the address schema, and add it to the Includes property
        ' of the customer schema.
        Dim import As XmlSchemaImport = New XmlSchemaImport()
        import.Namespace = "http://www.example.com/IPO"
        import.Schema = addressSchema
        customerSchema.Includes.Add(import)

        ' Reprocess and compile the modified XmlSchema object 
        ' of the customer schema and write it to the console.    
        schemaSet.Reprocess(customerSchema)
        schemaSet.Compile()
        customerSchema.Write(Console.Out)

        ' Recursively write all of the schemas imported into the
        ' customer schema to the console using the Includes 
        ' property of the customer schema.
        RecurseExternals(customerSchema)
    End Sub

    Shared Sub RecurseExternals(ByVal schema As XmlSchema)
        For Each external As XmlSchemaExternal In Schema.Includes

            If Not external.SchemaLocation = Nothing Then
                Console.WriteLine("External SchemaLocation: {0}", external.SchemaLocation)
            End If

            If external.GetType() Is GetType(XmlSchemaImport) Then
                Dim import As XmlSchemaImport = CType(external, XmlSchemaImport)
                Console.WriteLine("Imported namespace: {0}", import.Namespace)
            End If

            If Not external.Schema Is Nothing Then
                external.Schema.Write(Console.Out)
                RecurseExternals(external.Schema)
            End If
        Next
    End Sub

    Shared Sub ValidationCallback(ByVal sender As Object, ByVal args As ValidationEventArgs)
        If args.Severity = XmlSeverityType.Warning Then
            Console.Write("WARNING: ")
        Else
            If args.Severity = XmlSeverityType.Error Then
                Console.Write("ERROR: ")
            End If
        End If
        Console.WriteLine(args.Message)
    End Sub
End Class
using System;
using System.Xml;
using System.Xml.Schema;

class XmlSchemaImportExample
{
    static void Main(string[] args)
    {
        // Add the customer and address schemas to a new XmlSchemaSet and compile them.
        // Any schema validation warnings and errors encountered reading or 
        // compiling the schemas are handled by the ValidationEventHandler delegate.
        XmlSchemaSet schemaSet = new XmlSchemaSet();
        schemaSet.ValidationEventHandler += new ValidationEventHandler(ValidationCallback);
        schemaSet.Add("http://www.tempuri.org", "customer.xsd");
        schemaSet.Add("http://www.example.com/IPO", "address.xsd");
        schemaSet.Compile();

        // Retrieve the compiled XmlSchema objects for the customer and
        // address schema from the XmlSchemaSet by iterating over 
        // the Schemas property.
        XmlSchema customerSchema = null;
        XmlSchema addressSchema = null;
        foreach (XmlSchema schema in schemaSet.Schemas())
        {
            if (schema.TargetNamespace == "http://www.tempuri.org")
                customerSchema = schema;
            else if (schema.TargetNamespace == "http://www.example.com/IPO")
                addressSchema = schema;
        }

        // Create an XmlSchemaImport object, set the Namespace property
        // to the namespace of the address schema, the Schema property 
        // to the address schema, and add it to the Includes property
        // of the customer schema.
        XmlSchemaImport import = new XmlSchemaImport();
        import.Namespace = "http://www.example.com/IPO";
        import.Schema = addressSchema;
        customerSchema.Includes.Add(import);

        // Reprocess and compile the modified XmlSchema object 
        // of the customer schema and write it to the console.    
        schemaSet.Reprocess(customerSchema);
        schemaSet.Compile();
        customerSchema.Write(Console.Out);

        // Recursively write all of the schemas imported into the
        // customer schema to the console using the Includes 
        // property of the customer schema.
        RecurseExternals(customerSchema);       
    }

    static void RecurseExternals(XmlSchema schema)
    {
        foreach (XmlSchemaExternal external in schema.Includes)
        {
            if (external.SchemaLocation != null)
            {
                Console.WriteLine("External SchemaLocation: {0}", external.SchemaLocation);
            }

            if (external is XmlSchemaImport)
            {
                XmlSchemaImport import = external as XmlSchemaImport;
                Console.WriteLine("Imported namespace: {0}", import.Namespace);
            }

            if (external.Schema != null)
            {
                external.Schema.Write(Console.Out);
                RecurseExternals(external.Schema);
            }
        }
    }

    static void ValidationCallback(object sender, ValidationEventArgs args)
    {
        if (args.Severity == XmlSeverityType.Warning)
            Console.Write("WARNING: ");
        else if (args.Severity == XmlSeverityType.Error)
            Console.Write("ERROR: ");

        Console.WriteLine(args.Message);
    }
}
#using <System.Xml.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Xml::Schema;

ref class XmlSchemaImportExample
{
public:

    static void Main()
    {
        // Add the customer and address schemas to a new XmlSchemaSet and compile them.
        // Any schema validation warnings and errors encountered reading or 
        // compiling the schemas are handled by the ValidationEventHandler delegate.
        XmlSchemaSet^ schemaSet = gcnew XmlSchemaSet();
        schemaSet->ValidationEventHandler += gcnew ValidationEventHandler(ValidationCallback);
        schemaSet->Add("http://www.tempuri.org", "customer.xsd");
        schemaSet->Add("http://www.example.com/IPO", "address.xsd");
        schemaSet->Compile();

        // Retrieve the compiled XmlSchema objects for the customer and
        // address schema from the XmlSchemaSet by iterating over 
        // the Schemas property.
        XmlSchema^ customerSchema = nullptr;
        XmlSchema^ addressSchema = nullptr;
        for each (XmlSchema^ schema in schemaSet->Schemas())
        {
            if (schema->TargetNamespace == "http://www.tempuri.org")
                customerSchema = schema;
            else if (schema->TargetNamespace == "http://www.example.com/IPO")
                addressSchema = schema;
        }

        // Create an XmlSchemaImport object, set the Namespace property
        // to the namespace of the address schema, the Schema property 
        // to the address schema, and add it to the Includes property
        // of the customer schema.
        XmlSchemaImport^ import = gcnew XmlSchemaImport();
        import->Namespace = "http://www.example.com/IPO";
        import->Schema = addressSchema;
        customerSchema->Includes->Add(import);

        // Reprocess and compile the modified XmlSchema object 
        // of the customer schema and write it to the console.    
        schemaSet->Reprocess(customerSchema);
        schemaSet->Compile();
        customerSchema->Write(Console::Out);

        // Recursively write all of the schemas imported into the
        // customer schema to the console using the Includes 
        // property of the customer schema.
        RecurseExternals(customerSchema);       
    }

    static void RecurseExternals(XmlSchema^ schema)
    {
        for each (XmlSchemaExternal^ external in schema->Includes)
        {
            if (external->SchemaLocation != nullptr)
            {
                Console::WriteLine("External SchemaLocation: {0}", external->SchemaLocation);
            }

            if (external::typeid == XmlSchemaImport::typeid)
            {
                XmlSchemaImport^ import = dynamic_cast<XmlSchemaImport^>(external);
                Console::WriteLine("Imported namespace: {0}", import->Namespace);
            }

            if (external->Schema != nullptr)
            {
                external->Schema->Write(Console::Out);
                RecurseExternals(external->Schema);
            }
        }
    }

    static void ValidationCallback(Object^ sender, ValidationEventArgs^ args)
    {
        if (args->Severity == XmlSeverityType::Warning)
            Console::Write("WARNING: ");
        else if (args->Severity == XmlSeverityType::Error)
            Console::Write("ERROR: ");

        Console::WriteLine(args->Message);
    }
};

int main()
{
    XmlSchemaImportExample::Main();
    return 0;
}
<?xml version="1.0" encoding="utf-8"?>
<xs:schema xmlns:tns="http://www.tempuri.org" targetNamespace="http://www.tempuri.org" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:import namespace="http://www.example.com/IPO" />
  <xs:element name="Customer">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="FirstName" type="xs:string" />
        <xs:element name="LastName" type="tns:LastNameType" />
      </xs:sequence>
      <xs:attribute name="CustomerId" type="xs:positiveInteger" use="required" /
>
    </xs:complexType>
  </xs:element>
  <xs:simpleType name="LastNameType">
    <xs:restriction base="xs:string">
      <xs:maxLength value="20" />
    </xs:restriction>
  </xs:simpleType>
</xs:schema>
<schema targetNamespace="http://www.example.com/IPO" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:ipo="http://www.example.com/IPO">
  <annotation>
    <documentation xml:lang="en">
      Addresses for International Purchase order schema
      Copyright 2000 Example.com. All rights reserved.
    </documentation>
  </annotation>
  <complexType name="Address">
    <sequence>
      <element name="name"   type="string"/>
      <element name="street" type="string"/>
      <element name="city"   type="string"/>
    </sequence>
  </complexType>
  <complexType name="USAddress">
    <complexContent>
      <extension base="ipo:Address">
        <sequence>
          <element name="state" type="ipo:USState"/>
          <element name="zip"   type="positiveInteger"/>
        </sequence>
      </extension>
    </complexContent>
  </complexType>
  <!-- other Address derivations for more countries or regions -->
  <simpleType name="USState">
    <restriction base="string">
      <enumeration value="AK"/>
      <enumeration value="AL"/>
      <enumeration value="AR"/>
      <!-- and so on ... -->
    </restriction>
  </simpleType>
</schema>

如需 <xs:import />、<xs:include /> 及 <xs:redefine /> 項目與 XmlSchemaImportXmlSchemaIncludeXmlSchemaRedefine 類別的詳細資訊,請參閱 W3C XML 結構描述 (英文) 及 System.Xml.Schema 命名空間類別參考文件。

請參閱

概念

XML 結構描述物件模型概觀

讀取及寫入 XML 結構描述

建置 XML 結構描述

周遊 XML 結構描述

編輯 XML 結構描述

用於結構描述編譯的 XmlSchemaSet