XmlDocument Costruttori

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

public:
 XmlDocument();

public XmlDocument ();

Public Sub New ()

Esempio

Di seguito è riportato un esempio di convalida del tempo di caricamento. Una convalida XmlReader del tipo di documento (DTD) viene passata al Load metodo e viene fornito un ValidationEventHandler oggetto per notificare agli utenti eventuali errori di convalida. In questo esempio viene trovato un errore di convalida, ma il documento viene ancora caricato. In alternativa, è possibile definire una convalida per generare un'eccezione e arrestare il processo di caricamento quando viene trovato un errore di convalida XmlReader non specificando .ValidationEventHandler Per altre informazioni sulla convalida dei dati XML, vedere la sezione Note della pagina di riferimento XmlReader.

#using <System.Xml.dll>

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

ref class XmlDocumentSample
{
private:
    static XmlReader^ reader;
    static String^ filename = "bookdtd.xml";

    // Display the validation error.
    static void ValidationCallback(Object^ sender, ValidationEventArgs^ args)
    {
        Console::WriteLine("Validation error loading: {0}", filename);
        Console::WriteLine(args->Message);
    }

public:
    static void Main()
    {
        ValidationEventHandler^ eventHandler = gcnew ValidationEventHandler(XmlDocumentSample::ValidationCallback);

        try
        {
            // Create the validating reader and specify DTD validation.
            XmlReaderSettings^ settings = gcnew XmlReaderSettings();
                        settings->DtdProcessing = DtdProcessing::Parse;
            settings->ValidationType = ValidationType::DTD;
            settings->ValidationEventHandler += eventHandler;

            reader = XmlReader::Create(filename, settings);

            // Pass the validating reader to the XML document.
            // Validation fails due to an undefined attribute, but the 
            // data is still loaded into the document.
            XmlDocument^ doc = gcnew XmlDocument();
            doc->Load(reader);
            Console::WriteLine(doc->OuterXml);
        }
        finally
        {
            if (reader != nullptr)
                reader->Close();
        }
    }
};

int main()
{
    XmlDocumentSample::Main();
    return 0;
}

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

namespace Microsoft.Samples.Xml
{
    sealed class XmlDocumentSample
    {
        private XmlDocumentSample() { }

        static XmlReader reader;
        static String filename = "bookdtd.xml";

        public static void Main()
        {

            ValidationEventHandler eventHandler = new ValidationEventHandler(XmlDocumentSample.ValidationCallback);

            try
            {
                // Create the validating reader and specify DTD validation.
                XmlReaderSettings settings = new XmlReaderSettings();
                settings.DtdProcessing = DtdProcessing.Parse;
                settings.ValidationType = ValidationType.DTD;
                settings.ValidationEventHandler += eventHandler;

                reader = XmlReader.Create(filename, settings);

                // Pass the validating reader to the XML document.
                // Validation fails due to an undefined attribute, but the
                // data is still loaded into the document.
                XmlDocument doc = new XmlDocument();
                doc.Load(reader);
                Console.WriteLine(doc.OuterXml);
            }
            finally
            {
                if (reader != null)
                    reader.Close();
            }
        }

        // Display the validation error.
        private static void ValidationCallback(object sender, ValidationEventArgs args)
        {
            Console.WriteLine("Validation error loading: {0}", filename);
            Console.WriteLine(args.Message);
        }
    }
}

Option Explicit On
Option Strict On

Imports System.Xml
Imports System.Xml.Schema

Namespace Microsoft.Samples.Xml

    NotInheritable Class XmlDocumentSample

        Private Sub New()

        End Sub

        Shared reader As XmlReader
        Shared filename As String = "bookdtd.xml"

        Public Shared Sub Main()


            Dim eventHandler As New ValidationEventHandler(AddressOf XmlDocumentSample.ValidationCallback)

            Try

                ' Create the validating reader and specify DTD validation.
                Dim settings As New XmlReaderSettings()
                settings.DtdProcessing = DtdProcessing.Parse
                settings.ValidationType = ValidationType.DTD
                AddHandler settings.ValidationEventHandler, eventHandler

                reader = XmlReader.Create(filename, settings)

                ' Pass the validating reader to the XML document.
                ' Validation fails due to an undefined attribute, but the 
                ' data is still loaded into the document.
                Dim doc As New XmlDocument()
                doc.Load(reader)
                Console.WriteLine(doc.OuterXml)
            
            Finally

                If Not (reader Is Nothing) Then
                    reader.Close()
                End If

            End Try

        End Sub

        ' Display the validation error.
        Private Shared Sub ValidationCallback(ByVal sender As Object, ByVal args As ValidationEventArgs)
            Console.WriteLine("Validation error loading: {0}", filename)
            Console.WriteLine(args.Message)
        End Sub

    End Class
End Namespace

Nell'esempio viene utilizzato il file bookDTD.xml come input.

<!DOCTYPE bookstore [
  <!ELEMENT bookstore (book)*> 
  <!ELEMENT book (title,author,price)>
  <!ATTLIST book genre CDATA #REQUIRED>
  <!ELEMENT title (#PCDATA)>
  <!ELEMENT author (#PCDATA)>
  <!ELEMENT price (#PCDATA)>]>
<bookstore>
  <book genre="fantasy"  ISBN="2-3631-4">
    <title>Oberon's Legacy</title>
    <author>Corets, Eva</author>
    <price>5.95</price>
  </book>
</bookstore>

Vedi anche

• Load(String)
• LoadXml(String)

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

protected public:
 XmlDocument(System::Xml::XmlImplementation ^ imp);

protected internal XmlDocument (System.Xml.XmlImplementation imp);

new System.Xml.XmlDocument : System.Xml.XmlImplementation -> System.Xml.XmlDocument

Protected Friend Sub New (imp As XmlImplementation)

Parametri

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

Origine:

XmlDocument.cs

public:
 XmlDocument(System::Xml::XmlNameTable ^ nt);

public XmlDocument (System.Xml.XmlNameTable nt);

new System.Xml.XmlDocument : System.Xml.XmlNameTable -> System.Xml.XmlDocument

Public Sub New (nt As XmlNameTable)

Parametri