XmlValueGetter Delegasikan
Definisi
Penting
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delegate yang digunakan oleh kelas XmlSchemaValidator untuk meneruskan nilai atribut, teks, dan spasi putih sebagai jenis Common Language Runtime (CLR) yang kompatibel dengan jenis XML Schema Definition Language (XSD) dari atribut, teks, atau spasi kosong.
public delegate System::Object ^ XmlValueGetter();public delegate object? XmlValueGetter();public delegate object XmlValueGetter();type XmlValueGetter = delegate of unit -> objPublic Delegate Function XmlValueGetter() As Object Tampilkan Nilai
Objek yang berisi atribut, teks, atau nilai spasi kosong. Objek adalah jenis CLR yang sesuai dengan jenis XSD dari atribut, teks, atau nilai spasi kosong.
Contoh
Contoh berikut memvalidasi file contosoBooks.xml terhadap skema contosoBooks.xsd. Contoh menggunakan kelas XmlSerializer untuk mendeserialisasi file contosoBooks.xml dan meneruskan nilai simpul ke metode kelas XmlSchemaValidator.
using System;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using System.Collections;
namespace Microsoft.Samples.Xml.Schema
{
class XmlSchemaValidatorExamples
{
static void Main()
{
// The XML document to deserialize into the XmlSerializer object.
XmlReader reader = XmlReader.Create("contosoBooks.xml");
// The XmlSerializer object.
XmlSerializer serializer = new XmlSerializer(typeof(ContosoBooks));
ContosoBooks books = (ContosoBooks)serializer.Deserialize(reader);
// The XmlSchemaSet object containing the schema used to validate the XML document.
XmlSchemaSet schemaSet = new XmlSchemaSet();
schemaSet.Add("http://www.contoso.com/books", "contosoBooks.xsd");
// The XmlNamespaceManager object used to handle namespaces.
XmlNamespaceManager manager = new XmlNamespaceManager(reader.NameTable);
// Assign a ValidationEventHandler to handle schema validation warnings and errors.
XmlSchemaValidator validator = new XmlSchemaValidator(reader.NameTable, schemaSet, manager, XmlSchemaValidationFlags.None);
validator.ValidationEventHandler += new ValidationEventHandler(SchemaValidationEventHandler);
// Initialize the XmlSchemaValidator object.
validator.Initialize();
// Validate the bookstore element, verify that all required attributes are present
// and prepare to validate child content.
validator.ValidateElement("bookstore", "http://www.contoso.com/books", null);
validator.GetUnspecifiedDefaultAttributes(new ArrayList());
validator.ValidateEndOfAttributes(null);
// Get the next exptected element in the bookstore context.
XmlSchemaParticle[] particles = validator.GetExpectedParticles();
XmlSchemaElement nextElement = particles[0] as XmlSchemaElement;
Console.WriteLine("Expected Element: '{0}'", nextElement.Name);
foreach (BookType book in books.Book)
{
// Validate the book element.
validator.ValidateElement("book", "http://www.contoso.com/books", null);
// Get the exptected attributes for the book element.
Console.Write("\nExpected attributes: ");
XmlSchemaAttribute[] attributes = validator.GetExpectedAttributes();
foreach (XmlSchemaAttribute attribute in attributes)
{
Console.Write("'{0}' ", attribute.Name);
}
Console.WriteLine();
// Validate the genre attribute and display its post schema validation information.
if (book.Genre != null)
{
validator.ValidateAttribute("genre", "", book.Genre, schemaInfo);
}
DisplaySchemaInfo();
// Validate the publicationdate attribute and display its post schema validation information.
if (book.PublicationDate != null)
{
validator.ValidateAttribute("publicationdate", "", dateTimeGetter(book.PublicationDate), schemaInfo);
}
DisplaySchemaInfo();
// Validate the ISBN attribute and display its post schema validation information.
if (book.Isbn != null)
{
validator.ValidateAttribute("ISBN", "", book.Isbn, schemaInfo);
}
DisplaySchemaInfo();
// After validating all the attributes for the current element with ValidateAttribute method,
// you must call GetUnspecifiedDefaultAttributes to validate the default attributes.
validator.GetUnspecifiedDefaultAttributes(new ArrayList());
// Verify that all required attributes of the book element are present
// and prepare to validate child content.
validator.ValidateEndOfAttributes(null);
// Validate the title element and its content.
validator.ValidateElement("title", "http://www.contoso.com/books", null);
validator.ValidateEndElement(null, book.Title);
// Validate the author element, verify that all required attributes are present
// and prepare to validate child content.
validator.ValidateElement("author", "http://www.contoso.com/books", null);
validator.GetUnspecifiedDefaultAttributes(new ArrayList());
validator.ValidateEndOfAttributes(null);
if (book.Author.Name != null)
{
// Validate the name element and its content.
validator.ValidateElement("name", "http://www.contoso.com/books", null);
validator.ValidateEndElement(null, book.Author.Name);
}
if (book.Author.FirstName != null)
{
// Validate the first-name element and its content.
validator.ValidateElement("first-name", "http://www.contoso.com/books", null);
validator.ValidateEndElement(null, book.Author.FirstName);
}
if (book.Author.LastName != null)
{
// Validate the last-name element and its content.
validator.ValidateElement("last-name", "http://www.contoso.com/books", null);
validator.ValidateEndElement(null, book.Author.LastName);
}
// Validate the content of the author element.
validator.ValidateEndElement(null);
// Validate the price element and its content.
validator.ValidateElement("price", "http://www.contoso.com/books", null);
validator.ValidateEndElement(null, book.Price);
// Validate the content of the book element.
validator.ValidateEndElement(null);
}
// Validate the content of the bookstore element.
validator.ValidateEndElement(null);
// Close the XmlReader object.
reader.Close();
}
static XmlSchemaInfo schemaInfo = new XmlSchemaInfo();
static object dateTimeGetterContent;
static object dateTimeGetterHandle()
{
return dateTimeGetterContent;
}
static XmlValueGetter dateTimeGetter(DateTime dateTime)
{
dateTimeGetterContent = dateTime;
return new XmlValueGetter(dateTimeGetterHandle);
}
static void DisplaySchemaInfo()
{
if (schemaInfo.SchemaElement != null)
{
Console.WriteLine("Element '{0}' with type '{1}' is '{2}'",
schemaInfo.SchemaElement.Name, schemaInfo.SchemaType, schemaInfo.Validity);
}
else if (schemaInfo.SchemaAttribute != null)
{
Console.WriteLine("Attribute '{0}' with type '{1}' is '{2}'",
schemaInfo.SchemaAttribute.Name, schemaInfo.SchemaType, schemaInfo.Validity);
}
}
static void SchemaValidationEventHandler(object sender, ValidationEventArgs e)
{
switch (e.Severity)
{
case XmlSeverityType.Error:
Console.WriteLine("\nError: {0}", e.Message);
break;
case XmlSeverityType.Warning:
Console.WriteLine("\nWarning: {0}", e.Message);
break;
}
}
}
[XmlRootAttribute("bookstore", Namespace = "http://www.contoso.com/books", IsNullable = false)]
public class ContosoBooks
{
[XmlElementAttribute("book")]
public BookType[] Book;
}
public class BookType
{
[XmlAttributeAttribute("genre")]
public string Genre;
[XmlAttributeAttribute("publicationdate", DataType = "date")]
public DateTime PublicationDate;
[XmlAttributeAttribute("ISBN")]
public string Isbn;
[XmlElementAttribute("title")]
public string Title;
[XmlElementAttribute("author")]
public BookAuthor Author;
[XmlElementAttribute("price")]
public Decimal Price;
}
public class BookAuthor
{
[XmlElementAttribute("name")]
public string Name;
[XmlElementAttribute("first-name")]
public string FirstName;
[XmlElementAttribute("last-name")]
public string LastName;
}
}
Imports System.Xml
Imports System.Xml.Schema
Imports System.Xml.Serialization
Imports System.Collections
Namespace Microsoft.Samples.Xml.Schema
Class XmlSchemaValidatorExamples
Shared Sub Main()
' The XML document to deserialize into the XmlSerializer object.
Dim reader As XmlReader = XmlReader.Create("contosoBooks.xml")
' The XmlSerializer object.
Dim serializer As XmlSerializer = New XmlSerializer(GetType(ContosoBooks))
Dim books As ContosoBooks = CType(serializer.Deserialize(reader), ContosoBooks)
' The XmlSchemaSet object containing the schema used to validate the XML document.
Dim schemaSet As XmlSchemaSet = New XmlSchemaSet()
schemaSet.Add("http://www.contoso.com/books", "contosoBooks.xsd")
' The XmlNamespaceManager object used to handle namespaces.
Dim manager As XmlNamespaceManager = New XmlNamespaceManager(reader.NameTable)
' Assign a ValidationEventHandler to handle schema validation warnings and errors.
Dim validator As XmlSchemaValidator = New XmlSchemaValidator(reader.NameTable, schemaSet, manager, XmlSchemaValidationFlags.None)
'validator.ValidationEventHandler += New ValidationEventHandler(SchemaValidationEventHandler)
AddHandler validator.ValidationEventHandler, AddressOf SchemaValidationEventHandler
' Initialize the XmlSchemaValidator object.
validator.Initialize()
' Validate the bookstore element, verify that all required attributes are present
' and prepare to validate child content.
validator.ValidateElement("bookstore", "http://www.contoso.com/books", Nothing)
validator.GetUnspecifiedDefaultAttributes(New ArrayList())
validator.ValidateEndOfAttributes(Nothing)
' Get the next exptected element in the bookstore context.
Dim particles() As XmlSchemaParticle = validator.GetExpectedParticles()
Dim nextElement As XmlSchemaElement = particles(0)
Console.WriteLine("Expected Element: '{0}'", nextElement.Name)
For Each book As BookType In books.book
' Validate the book element.
validator.ValidateElement("book", "http://www.contoso.com/books", Nothing)
' Get the exptected attributes for the book element.
Console.Write(vbCrLf & "Expected attributes: ")
Dim attributes() As XmlSchemaAttribute = validator.GetExpectedAttributes()
For Each attribute As XmlSchemaAttribute In attributes
Console.Write("'{0}' ", attribute.Name)
Next
Console.WriteLine()
' Validate the genre attribute and display its post schema validation information.
If Not book.Genre Is Nothing Then
validator.ValidateAttribute("genre", "", book.Genre, schemaInfo)
End If
DisplaySchemaInfo()
' Validate the publicationdate attribute and display its post schema validation information.
If Not book.PublicationDate = Nothing Then
validator.ValidateAttribute("publicationdate", "", dateTimeGetter(book.PublicationDate), schemaInfo)
End If
DisplaySchemaInfo()
' Validate the ISBN attribute and display its post schema validation information.
If Not book.Isbn Is Nothing Then
validator.ValidateAttribute("ISBN", "", book.Isbn, schemaInfo)
End If
DisplaySchemaInfo()
' After validating all the attributes for the current element with ValidateAttribute method,
' you must call GetUnspecifiedDefaultAttributes to validate the default attributes.
validator.GetUnspecifiedDefaultAttributes(New ArrayList())
' Verify that all required attributes of the book element are present
' and prepare to validate child content.
validator.ValidateEndOfAttributes(Nothing)
' Validate the title element and its content.
validator.ValidateElement("title", "http://www.contoso.com/books", Nothing)
validator.ValidateEndElement(Nothing, book.Title)
' Validate the author element, verify that all required attributes are present
' and prepare to validate child content.
validator.ValidateElement("author", "http://www.contoso.com/books", Nothing)
validator.GetUnspecifiedDefaultAttributes(New ArrayList())
validator.ValidateEndOfAttributes(Nothing)
If Not book.Author.Name Is Nothing Then
' Validate the name element and its content.
validator.ValidateElement("name", "http://www.contoso.com/books", Nothing)
validator.ValidateEndElement(Nothing, book.Author.Name)
End If
If Not book.Author.FirstName Is Nothing Then
' Validate the first-name element and its content.
validator.ValidateElement("first-name", "http://www.contoso.com/books", Nothing)
validator.ValidateEndElement(Nothing, book.Author.FirstName)
End If
If Not book.Author.LastName Is Nothing Then
' Validate the last-name element and its content.
validator.ValidateElement("last-name", "http://www.contoso.com/books", Nothing)
validator.ValidateEndElement(Nothing, book.Author.LastName)
End If
' Validate the content of the author element.
validator.ValidateEndElement(Nothing)
' Validate the price element and its content.
validator.ValidateElement("price", "http://www.contoso.com/books", Nothing)
validator.ValidateEndElement(Nothing, book.Price)
' Validate the content of the book element.
validator.ValidateEndElement(Nothing)
Next
' Validate the content of the bookstore element.
validator.ValidateEndElement(Nothing)
' Close the XmlReader object.
reader.Close()
End Sub
Shared schemaInfo As XmlSchemaInfo = New XmlSchemaInfo()
Shared dateTimeGetterContent As Object
Shared Function dateTimeGetterHandle() As Object
Return dateTimeGetterContent
End Function
Shared Function dateTimeGetter(ByVal dateTime As DateTime) As XmlValueGetter
dateTimeGetterContent = dateTime
Return New XmlValueGetter(AddressOf dateTimeGetterHandle)
End Function
Shared Sub DisplaySchemaInfo()
If Not schemaInfo.SchemaElement Is Nothing Then
Console.WriteLine("Element '{0}' with type '{1}' is '{2}'", schemaInfo.SchemaElement.Name, schemaInfo.SchemaType, schemaInfo.Validity)
ElseIf Not schemaInfo.SchemaAttribute Is Nothing Then
Console.WriteLine("Attribute '{0}' with type '{1}' is '{2}'", schemaInfo.SchemaAttribute.Name, schemaInfo.SchemaType, schemaInfo.Validity)
End If
End Sub
Shared Sub SchemaValidationEventHandler(ByVal sender As Object, ByVal e As ValidationEventArgs)
Select Case e.Severity
Case XmlSeverityType.Error
Console.WriteLine(vbCrLf & "Error: {0}", e.Message)
Exit Sub
Case XmlSeverityType.Warning
Console.WriteLine(vbCrLf & "Warning: {0}", e.Message)
Exit Sub
End Select
End Sub
End Class
<XmlRootAttribute("bookstore", Namespace:="http://www.contoso.com/books", IsNullable:=False)> _
Public Class ContosoBooks
<XmlElementAttribute("book")> _
Public book() As BookType
End Class
Public Class BookType
<XmlAttributeAttribute("genre")> _
Public Genre As String
<XmlAttributeAttribute("publicationdate", DataType:="date")> _
Public PublicationDate As DateTime
<XmlAttributeAttribute("ISBN")> _
Public Isbn As String
<XmlElementAttribute("title")> _
Public Title As String
<XmlElementAttribute("author")> _
Public Author As BookAuthor
<XmlElementAttribute("price")> _
Public Price As Decimal
End Class
Public Class BookAuthor
<XmlElementAttribute("name")> _
Public Name As String
<XmlElementAttribute("first-name")> _
Public FirstName As String
<XmlElementAttribute("last-name")> _
Public LastName As String
End Class
End Namespace
Contoh mengambil file contosoBooks.xml sebagai input.
<?xml version="1.0" encoding="utf-8" ?>
<bookstore xmlns="http://www.contoso.com/books">
<book genre="autobiography" publicationdate="1981-03-22" ISBN="1-861003-11-0">
<title>The Autobiography of Benjamin Franklin</title>
<author>
<first-name>Benjamin</first-name>
<last-name>Franklin</last-name>
</author>
<price>8.99</price>
</book>
<book genre="novel" publicationdate="1967-11-17" ISBN="0-201-63361-2">
<title>The Confidence Man</title>
<author>
<first-name>Herman</first-name>
<last-name>Melville</last-name>
</author>
<price>11.99</price>
</book>
<book genre="philosophy" publicationdate="1991-02-15" ISBN="1-861001-57-6">
<title>The Gorgias</title>
<author>
<name>Plato</name>
</author>
<price>9.99</price>
</book>
</bookstore>
Contohnya juga mengambil contosoBooks.xsd sebagai input.
<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.contoso.com/books" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="bookstore">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded" name="book">
<xs:complexType>
<xs:sequence>
<xs:element name="title" type="xs:string" />
<xs:element name="author">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" name="name" type="xs:string" />
<xs:element minOccurs="0" name="first-name" type="xs:string" />
<xs:element minOccurs="0" name="last-name" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="price" type="xs:decimal" />
</xs:sequence>
<xs:attribute name="genre" type="xs:string" use="required" />
<xs:attribute name="publicationdate" type="xs:date" use="required" />
<xs:attribute name="ISBN" type="xs:string" use="required" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
Keterangan
XmlValueGetter
delegate berguna jika nilai CLR dari atribut, teks, atau node spasi putih sudah tersedia, dan menghindari biaya konversi ke string lalu membandingkannya lagi untuk validasi.
Untuk informasi selengkapnya tentang kelas
Metode Ekstensi
| GetMethodInfo(Delegate) |
Mendapatkan objek yang mewakili metode yang diwakili oleh delegasi yang ditentukan. |
Berlaku untuk
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