编辑 XML 架构

编辑 XML 架构是架构对象模型 (SOM) 最重要的功能之一。 SOM 的所有前架构编译属性均可以用于更改 XML 架构中的现有值。 然后,可以重新编译 XML 架构以反映更改。

编辑加载到 SOM 中的架构的第一步是遍历架构。 在尝试编辑架构之前,应熟悉如何使用 SOM API 遍历架构。 还应熟悉后架构编译信息集 (PSCI) 的前架构编译属性和后架构编译属性。

编辑 XML 架构

此部分中收录了两个代码示例,均编辑生成 XML 架构主题中创建的客户架构。 第一个代码示例向 PhoneNumber 元素中添加新的 Customer 元素,第二个代码示例向 Title 元素中添加新的 FirstName 属性。 第一个示例还使用后架构编译 XmlSchema.Elements 集合遍历客户架构,而第二个代码示例使用前架构编译 XmlSchema.Items 集合遍历客户架构。

PhoneNumber 元素示例

第一个代码示例向客户架构的 PhoneNumber 元素中添加新的 Customer 元素。 代码示例通过下列步骤编辑客户架构。

  1. 将客户架构添加到新的 XmlSchemaSet 对象并进行编译。 在读取或编译架构时遇到的任何架构验证警告和错误由 ValidationEventHandler 委托进行处理。

  2. 通过循环访问 XmlSchema 属性,从 XmlSchemaSet 中检索已编译的 Schemas 对象。 因为架构已编译,所以,可以访问后架构编译信息集 (PSCI) 属性。

  3. 使用 PhoneNumber 类创建 XmlSchemaElement 元素,使用 xs:stringXmlSchemaSimpleType 类创建 XmlSchemaSimpleTypeRestriction 简单类型限制,将模式方面添加到限制的 Facets 属性,然后将限制添加到简单类型的 Content 并将简单类型添加到 SchemaType 元素的 PhoneNumber

  4. 在后架构编译 XmlSchemaElement 集合的 Values 集合中循环访问每个 XmlSchema.Elements

  5. 如果元素的 QualifiedName"Customer",请使用 Customer 类获取 XmlSchemaComplexType 元素的复杂类型并使用 XmlSchemaSequence 类获取复杂类型的序列粒子。

  6. 使用序列的前架构编译 PhoneNumber 集合将新的 FirstName 元素添加到包含现有 LastNameItems 元素的序列中。

  7. 最后,使用 XmlSchema 类的 ReprocessCompile 方法重新处理并编译已修改的 XmlSchemaSet 对象并将其写入控制台。

以下是完整的代码示例。

#using <System.Xml.dll>

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

ref class XmlSchemaEditExample
{
public:

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

        // Retrieve the compiled XmlSchema object from the XmlSchemaSet
        // by iterating over the Schemas property.
        XmlSchema^ customerSchema = nullptr;
        for each (XmlSchema^ schema in schemaSet->Schemas())
        {
            customerSchema = schema;
        }

        // Create the PhoneNumber element.
        XmlSchemaElement^ phoneElement = gcnew XmlSchemaElement();
        phoneElement->Name = "PhoneNumber";

        // Create the xs:string simple type restriction.
        XmlSchemaSimpleType^ phoneType = gcnew XmlSchemaSimpleType();
        XmlSchemaSimpleTypeRestriction^ restriction =
            gcnew XmlSchemaSimpleTypeRestriction();
        restriction->BaseTypeName = gcnew XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        // Add a pattern facet to the restriction.
        XmlSchemaPatternFacet^ phonePattern = gcnew XmlSchemaPatternFacet();
        phonePattern->Value = "\\d{3}-\\d{3}-\\d(4)";
        restriction->Facets->Add(phonePattern);

        // Add the restriction to the Content property of the simple type
        // and the simple type to the SchemaType of the PhoneNumber element.
        phoneType->Content = restriction;
        phoneElement->SchemaType = phoneType;

        // Iterate over each XmlSchemaElement in the Values collection
        // of the Elements property.
        for each (XmlSchemaElement^ element in customerSchema->Elements->Values)
        {
            // If the qualified name of the element is "Customer", 
            // get the complex type of the Customer element  
            // and the sequence particle of the complex type.
            if (element->QualifiedName->Name->Equals("Customer"))
            {
                XmlSchemaComplexType^ customerType =
                    dynamic_cast<XmlSchemaComplexType^>(element->ElementSchemaType);
                XmlSchemaSequence^ sequence =
                    dynamic_cast<XmlSchemaSequence^>(customerType->Particle);

                // Add the new PhoneNumber element to the sequence.
                sequence->Items->Add(phoneElement);
            }
        }

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

    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()
{
    XmlSchemaEditExample::Main();
    return 0;
}
using System;
using System.Xml;
using System.Xml.Schema;

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

        // Retrieve the compiled XmlSchema object from the XmlSchemaSet
        // by iterating over the Schemas property.
        XmlSchema customerSchema = null;
        foreach (XmlSchema schema in schemaSet.Schemas())
        {
            customerSchema = schema;
        }

        // Create the PhoneNumber element.
        XmlSchemaElement phoneElement = new XmlSchemaElement();
        phoneElement.Name = "PhoneNumber";

        // Create the xs:string simple type restriction.
        XmlSchemaSimpleType phoneType = new XmlSchemaSimpleType();
        XmlSchemaSimpleTypeRestriction restriction =
            new XmlSchemaSimpleTypeRestriction();
        restriction.BaseTypeName = new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        // Add a pattern facet to the restriction.
        XmlSchemaPatternFacet phonePattern = new XmlSchemaPatternFacet();
        phonePattern.Value = "\\d{3}-\\d{3}-\\d(4)";
        restriction.Facets.Add(phonePattern);

        // Add the restriction to the Content property of the simple type
        // and the simple type to the SchemaType of the PhoneNumber element.
        phoneType.Content = restriction;
        phoneElement.SchemaType = phoneType;

        // Iterate over each XmlSchemaElement in the Values collection
        // of the Elements property.
        foreach (XmlSchemaElement element in customerSchema.Elements.Values)
        {
            // If the qualified name of the element is "Customer",
            // get the complex type of the Customer element
            // and the sequence particle of the complex type.
            if (element.QualifiedName.Name.Equals("Customer"))
            {
                XmlSchemaComplexType customerType =
                    element.ElementSchemaType as XmlSchemaComplexType;
                XmlSchemaSequence sequence =
                    customerType.Particle as XmlSchemaSequence;

                // Add the new PhoneNumber element to the sequence.
                sequence.Items.Add(phoneElement);
            }
        }

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

    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);
    }
}
Imports System.Xml
Imports System.Xml.Schema

Class XmlSchemaEditExample

    Shared Sub Main()

        ' Add the customer schema to a new XmlSchemaSet and compile it.
        ' Any schema validation warnings and errors encountered reading or 
        ' compiling the schema 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.Compile()

        ' Retrieve the compiled XmlSchema object from the XmlSchemaSet
        ' by iterating over the Schemas property.
        Dim customerSchema As XmlSchema = Nothing
        For Each schema As XmlSchema In schemaSet.Schemas()
            customerSchema = schema
        Next

        ' Create the PhoneNumber element.
        Dim phoneElement As XmlSchemaElement = New XmlSchemaElement()
        phoneElement.Name = "PhoneNumber"

        ' Create the xs:string simple type restriction.
        Dim phoneType As XmlSchemaSimpleType = New XmlSchemaSimpleType()
        Dim restriction As XmlSchemaSimpleTypeRestriction = _
            New XmlSchemaSimpleTypeRestriction()
        restriction.BaseTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        ' Add a pattern facet to the restriction.
        Dim phonePattern As XmlSchemaPatternFacet = New XmlSchemaPatternFacet()
        phonePattern.Value = "\\d{3}-\\d{3}-\\d(4)"
        restriction.Facets.Add(phonePattern)

        ' Add the restriction to the Content property of the simple type
        ' and the simple type to the SchemaType of the PhoneNumber element.
        phoneType.Content = restriction
        phoneElement.SchemaType = phoneType

        ' Iterate over each XmlSchemaElement in the Values collection
        ' of the Elements property.
        For Each element As XmlSchemaElement In customerSchema.Elements.Values

            ' If the qualified name of the element is "Customer", 
            ' get the complex type of the Customer element  
            ' and the sequence particle of the complex type.
            If element.QualifiedName.Name.Equals("Customer") Then

                Dim customerType As XmlSchemaComplexType = _
                    CType(element.ElementSchemaType, XmlSchemaComplexType)
                Dim sequence As XmlSchemaSequence = _
                    CType(customerType.Particle, XmlSchemaSequence)

                ' Add the new PhoneNumber element to the sequence.
                sequence.Items.Add(phoneElement)
            End If
        Next

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

下面展示了生成 XML 架构主题中创建的已修改客户架构。

<?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:element name="Customer">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="FirstName" type="xs:string" />
        <xs:element name="LastName" type="tns:LastNameType" />
        <xs:element name="PhoneNumber">           <xs:simpleType>             <xs:restriction base="xs:string">               <xs:pattern value="\d{3}-\d{3}-\d(4)" />             </xs:restriction>           </xs:simpleType>         </xs:element>
      </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>

Title 属性示例

第二个代码示例向客户架构的 Title 元素中添加新的 FirstName 属性。 在第一个代码示例中,FirstName 元素的类型为 xs:string。 为了使 FirstName 元素包含属性以及字符串内容,其类型必须使用简单内容扩展内容模型更改为复杂类型。

代码示例通过下列步骤编辑客户架构。

  1. 将客户架构添加到新的 XmlSchemaSet 对象并进行编译。 在读取或编译架构时遇到的任何架构验证警告和错误由 ValidationEventHandler 委托进行处理。

  2. 通过循环访问 XmlSchema 属性,从 XmlSchemaSet 中检索已编译的 Schemas 对象。 因为架构已编译,所以,可以访问后架构编译信息集 (PSCI) 属性。

  3. 使用 FirstName 类为 XmlSchemaComplexType 元素创建新的复杂类型。

  4. 使用 xs:stringXmlSchemaSimpleContent 类创建新的简单内容扩展,基类型为 XmlSchemaSimpleContentExtension

  5. 使用 Title 类创建新的 XmlSchemaAttribute 属性,SchemaTypeNamexs:string,并将该属性添加到简单内容扩展。

  6. 将简单内容的内容模型设置为简单内容扩展,将复杂类型的内容模型设置为简单内容。

  7. 将新的复杂类型添加到前架构编译 XmlSchema.Items 集合。

  8. 在前架构编译 XmlSchemaObject 集合中循环访问每个 XmlSchema.Items

注意

因为 FirstName 元素不是架构中的全局元素,所以,不能在 XmlSchema.ItemsXmlSchema.Elements 集合中使用。 代码示例通过首先定位 FirstName 元素来定位 Customer 元素。

第一个代码示例使用后架构编译 XmlSchema.Elements 集合遍历了架构。 在此示例中,前架构编译 XmlSchema.Items 集合用于遍历架构。 尽管两个集合均提供对架构中的全局元素的访问,但是循环访问 Items 集合使用的时间更长,因为必须循环访问架构中的所有全局元素,没有任何 PSCI 属性。 PSCI 集合(XmlSchema.ElementsXmlSchema.AttributesXmlSchema.SchemaTypes 等)提供对其全局元素、属性和类型及其 PSCI 属性的直接访问。

  1. 如果 XmlSchemaObject 为元素,该元素的 QualifiedName"Customer",请使用 Customer 类获取 XmlSchemaComplexType 元素的复杂类型并使用 XmlSchemaSequence 类获取复杂类型的序列粒子。

  2. 在前架构编译 XmlSchemaParticle 集合中循环访问每个 XmlSchemaSequence.Items

  3. 如果 XmlSchemaParticle 为元素,该元素的 QualifiedName"FirstName",请将 SchemaTypeName 元素的 FirstName 设置为新的 FirstName 复杂类型。

  4. 最后,使用 XmlSchema 类的 ReprocessCompile 方法重新处理并编译已修改的 XmlSchemaSet 对象并将其写入控制台。

以下是完整的代码示例。

#using <System.Xml.dll>

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

ref class XmlSchemaEditExample
{
public:

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

        // Retrieve the compiled XmlSchema object from the XmlSchemaSet
        // by iterating over the Schemas property.
        XmlSchema^ customerSchema = nullptr;
        for each (XmlSchema^ schema in schemaSet->Schemas())
        {
            customerSchema = schema;
        }

        // Create a complex type for the FirstName element.
        XmlSchemaComplexType^ complexType = gcnew XmlSchemaComplexType();
        complexType->Name = "FirstNameComplexType";
        
        // Create a simple content extension with a base type of xs:string.
        XmlSchemaSimpleContent^ simpleContent = gcnew XmlSchemaSimpleContent();
        XmlSchemaSimpleContentExtension^ simpleContentExtension =
            gcnew XmlSchemaSimpleContentExtension();
        simpleContentExtension->BaseTypeName =
            gcnew XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        // Create the new Title attribute with a SchemaTypeName of xs:string
        // and add it to the simple content extension.
        XmlSchemaAttribute^ attribute = gcnew XmlSchemaAttribute();
        attribute->Name = "Title";
        attribute->SchemaTypeName =
            gcnew XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");
        simpleContentExtension->Attributes->Add(attribute);

        // Set the content model of the simple content to the simple content extension
        // and the content model of the complex type to the simple content.
        simpleContent->Content = simpleContentExtension;
        complexType->ContentModel = simpleContent;

        // Add the new complex type to the pre-schema-compilation Items collection.
        customerSchema->Items->Add(complexType);

        // Iterate over each XmlSchemaObject in the pre-schema-compilation
        // Items collection.
        for each (XmlSchemaObject^ schemaObject in customerSchema->Items)
        {
            // If the XmlSchemaObject is an element, whose QualifiedName
            // is "Customer", get the complex type of the Customer element
            // and the sequence particle of the complex type.
            if (schemaObject::typeid == XmlSchemaElement::typeid)
            {
                XmlSchemaElement^ element = dynamic_cast<XmlSchemaElement^>(schemaObject);

                if (element->QualifiedName->Name->Equals("Customer"))
                {
                    XmlSchemaComplexType^ customerType =
                        dynamic_cast<XmlSchemaComplexType^>(element->ElementSchemaType);

                    XmlSchemaSequence^ sequence =
                        dynamic_cast<XmlSchemaSequence^>(customerType->Particle);

                    // Iterate over each XmlSchemaParticle in the pre-schema-compilation
                    // Items property.
                    for each (XmlSchemaParticle^ particle in sequence->Items)
                    {
                        // If the XmlSchemaParticle is an element, who's QualifiedName
                        // is "FirstName", set the SchemaTypeName of the FirstName element
                        // to the new FirstName complex type.
                        if (particle::typeid == XmlSchemaElement::typeid)
                        {
                            XmlSchemaElement^ childElement =
                                dynamic_cast<XmlSchemaElement^>(particle);

                            if (childElement->Name->Equals("FirstName"))
                            {
                                childElement->SchemaTypeName =
                                    gcnew XmlQualifiedName("FirstNameComplexType",
                                    "http://www.tempuri.org");
                            }
                        }
                    }
                }
            }
        }

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

    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()
{
    XmlSchemaEditExample::Main();
    return 0;
}
using System;
using System.Xml;
using System.Xml.Schema;

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

        // Retrieve the compiled XmlSchema object from the XmlSchemaSet
        // by iterating over the Schemas property.
        XmlSchema customerSchema = null;
        foreach (XmlSchema schema in schemaSet.Schemas())
        {
            customerSchema = schema;
        }

        // Create a complex type for the FirstName element.
        XmlSchemaComplexType complexType = new XmlSchemaComplexType();
        complexType.Name = "FirstNameComplexType";

        // Create a simple content extension with a base type of xs:string.
        XmlSchemaSimpleContent simpleContent = new XmlSchemaSimpleContent();
        XmlSchemaSimpleContentExtension simpleContentExtension =
            new XmlSchemaSimpleContentExtension();
        simpleContentExtension.BaseTypeName =
            new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");

        // Create the new Title attribute with a SchemaTypeName of xs:string
        // and add it to the simple content extension.
        XmlSchemaAttribute attribute = new XmlSchemaAttribute();
        attribute.Name = "Title";
        attribute.SchemaTypeName =
            new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");
        simpleContentExtension.Attributes.Add(attribute);

        // Set the content model of the simple content to the simple content extension
        // and the content model of the complex type to the simple content.
        simpleContent.Content = simpleContentExtension;
        complexType.ContentModel = simpleContent;

        // Add the new complex type to the pre-schema-compilation Items collection.
        customerSchema.Items.Add(complexType);

        // Iterate over each XmlSchemaObject in the pre-schema-compilation
        // Items collection.
        foreach (XmlSchemaObject schemaObject in customerSchema.Items)
        {
            // If the XmlSchemaObject is an element, whose QualifiedName
            // is "Customer", get the complex type of the Customer element
            // and the sequence particle of the complex type.
            if (schemaObject is XmlSchemaElement)
            {
                XmlSchemaElement element = schemaObject as XmlSchemaElement;

                if (element.QualifiedName.Name.Equals("Customer"))
                {
                    XmlSchemaComplexType customerType =
                        element.ElementSchemaType as XmlSchemaComplexType;

                    XmlSchemaSequence sequence =
                        customerType.Particle as XmlSchemaSequence;

                    // Iterate over each XmlSchemaParticle in the pre-schema-compilation
                    // Items property.
                    foreach (XmlSchemaParticle particle in sequence.Items)
                    {
                        // If the XmlSchemaParticle is an element, who's QualifiedName
                        // is "FirstName", set the SchemaTypeName of the FirstName element
                        // to the new FirstName complex type.
                        if (particle is XmlSchemaElement)
                        {
                            XmlSchemaElement childElement =
                                particle as XmlSchemaElement;

                            if (childElement.Name.Equals("FirstName"))
                            {
                                childElement.SchemaTypeName =
                                    new XmlQualifiedName("FirstNameComplexType",
                                    "http://www.tempuri.org");
                            }
                        }
                    }
                }
            }
        }

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

    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);
    }
}
Imports System.Xml
Imports System.Xml.Schema

Class XmlSchemaEditExample

    Shared Sub Main()

        ' Add the customer schema to a new XmlSchemaSet and compile it.
        ' Any schema validation warnings and errors encountered reading or 
        ' compiling the schema 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.Compile()

        ' Retrieve the compiled XmlSchema object from the XmlSchemaSet
        ' by iterating over the Schemas property.
        Dim customerSchema As XmlSchema = Nothing
        For Each schema As XmlSchema In schemaSet.Schemas()
            customerSchema = schema
        Next

        ' Create a complex type for the FirstName element.
        Dim complexType As XmlSchemaComplexType = New XmlSchemaComplexType()
        complexType.Name = "FirstNameComplexType"

        ' Create a simple content extension with a base type of xs:string.
        Dim simpleContent As XmlSchemaSimpleContent = New XmlSchemaSimpleContent()
        Dim simpleContentExtension As XmlSchemaSimpleContentExtension = _
            New XmlSchemaSimpleContentExtension()
        simpleContentExtension.BaseTypeName = _
            New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        ' Create the new Title attribute with a SchemaTypeName of xs:string
        ' and add it to the simple content extension.
        Dim attribute As XmlSchemaAttribute = New XmlSchemaAttribute()
        attribute.Name = "Title"
        attribute.SchemaTypeName = _
            New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")
        simpleContentExtension.Attributes.Add(attribute)

        ' Set the content model of the simple content to the simple content extension
        ' and the content model of the complex type to the simple content.
        simpleContent.Content = simpleContentExtension
        complexType.ContentModel = simpleContent

        ' Add the new complex type to the pre-schema-compilation Items collection.
        customerSchema.Items.Add(complexType)

        ' Iterate over each XmlSchemaObject in the pre-schema-compilation
        ' Items collection.
        For Each schemaObject As XmlSchemaObject In customerSchema.Items

            ' If the XmlSchemaObject is an element, whose QualifiedName
            ' is "Customer", get the complex type of the Customer element
            ' and the sequence particle of the complex type.
            If schemaObject.GetType() Is GetType(XmlSchemaElement) Then

                Dim element As XmlSchemaElement = CType(schemaObject, XmlSchemaElement)

                If (element.QualifiedName.Name.Equals("Customer")) Then
                    Dim customerType As XmlSchemaComplexType = _
                        CType(element.ElementSchemaType, XmlSchemaComplexType)

                    Dim sequence As XmlSchemaSequence = _
                       CType(customerType.Particle, XmlSchemaSequence)

                    ' Iterate over each XmlSchemaParticle in the pre-schema-compilation
                    ' Items property.
                    For Each particle As XmlSchemaParticle In sequence.Items

                        ' If the XmlSchemaParticle is an element, who's QualifiedName
                        ' is "FirstName", set the SchemaTypeName of the FirstName element
                        ' to the new FirstName complex type.
                        If particle.GetType() Is GetType(XmlSchemaElement) Then
                            Dim childElement As XmlSchemaElement = _
                                CType(particle, XmlSchemaElement)

                            If childElement.Name.Equals("FirstName") Then
                                childElement.SchemaTypeName = _
                                   New XmlQualifiedName("FirstNameComplexType", _
                                  "http://www.tempuri.org")
                            End If
                        End If
                    Next
                End If
            End If
        Next

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

下面展示了生成 XML 架构主题中创建的已修改客户架构。

<?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:element name="Customer">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="FirstName" type="tns:FirstNameComplexType" />
        <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:complexType name="FirstNameComplexType">     <xs:simpleContent>       <xs:extension base="xs:string">         <xs:attribute name="Title" type="xs:string" />       </xs:extension>     </xs:simpleContent>   </xs:complexType>
</xs:schema>

请参阅