XmlValueGetter Delegat
Definition
Wichtig
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Ein delegate, der von der XmlSchemaValidator-Klasse zum Übergeben von Attribut-, Text- und Leerraumwerten als CLR-Typ (Common Language Runtime) verwendet wird, die kompatibel sind mit dem XSD-Typ (XML Schema Definition Language) des Attributs, Texts oder Leerraums.
public delegate System::Object ^ XmlValueGetter();public delegate object? XmlValueGetter();public delegate object XmlValueGetter();type XmlValueGetter = delegate of unit -> objPublic Delegate Function XmlValueGetter() As Object Rückgabewert
Ein Objekt, das den Attribut-, Text- oder Leerraumwert enthält. Das Objekt ist ein CLR-Typ, der dem XSD-Typ des Attribut-, Text- oder Leerraumwerts entspricht.
Beispiele
Im folgenden Beispiel wird die Datei anhand des contosoBooks.xml contosoBooks.xsd Schemas überprüft. Im Beispiel wird mit der XmlSerializer-Klasse die contosoBooks.xml-Datei deserialisiert, und der Wert der Knoten wird an die Methoden der XmlSchemaValidator-Klasse übergeben.
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
In diesem Beispiel wird die Datei contosoBooks.xml als Eingabe verwendet.
<?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>
In diesem Beispiel wird auch contosoBooks.xsd als Eingabe verwendet.
<?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>
Hinweise
Es XmlValueGetter delegate ist nützlich, wenn der CLR-Wert eines Attributs, eines Text- oder Leerraumknotens bereits verfügbar ist und die Kosten der Konvertierung in ein string und dann erneut für die Überprüfung erstellt werden.
Weitere Informationen zur Klasse finden Sie im Thema "XmlSchemaValidator Push-Based Validierung" oder in der XmlSchemaValidator XmlSchemaValidator Klassenreferenzdokumentation.
Erweiterungsmethoden
| GetMethodInfo(Delegate) |
Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird. |