XmlNodeReader.Read Método

Definición

Lee el siguiente nodo del flujo.

public:
 override bool Read();
public override bool Read ();
override this.Read : unit -> bool
Public Overrides Function Read () As Boolean

Devoluciones

Boolean

Es true si se lee correctamente el siguiente nodo; es false si no hay más nodos que leer.

Ejemplos

En el ejemplo siguiente se lee un XML y se muestra cada nodo.

#using <System.Xml.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
int main()
{
   String^ filename = "items.xml";
   XmlNodeReader^ reader = nullptr;
   try
   {
      
      //Create an XmlNodeReader to read the XmlDocument.
      XmlDocument^ doc = gcnew XmlDocument;
      doc->Load( filename );
      reader = gcnew XmlNodeReader( doc );
      
      //Parse the file and display each of the nodes.
      while ( reader->Read() )
      {
         switch ( reader->NodeType )
         {
            case XmlNodeType::Element:
               Console::Write( "<{0}>", reader->Name );
               break;

            case XmlNodeType::Text:
               Console::Write( reader->Value );
               break;

            case XmlNodeType::CDATA:
               Console::Write( reader->Value );
               break;

            case XmlNodeType::ProcessingInstruction:
               Console::Write( "<?{0} {1}?>", reader->Name, reader->Value );
               break;

            case XmlNodeType::Comment:
               Console::Write( "<!--{0}-->", reader->Value );
               break;

            case XmlNodeType::XmlDeclaration:
               Console::Write( "<?xml version='1.0'?>" );
               break;

            case XmlNodeType::Document:
               break;

            case XmlNodeType::EndElement:
               Console::Write( "</{0}>", reader->Name );
               break;
         }
      }
   }
   finally
   {
      if ( reader != nullptr )
            reader->Close();
   }

}
using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }
          }
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class
Imports System.IO
Imports System.Xml

Public Class Sample
    Private Const filename As String = "items.xml"
    Public Shared Sub Main()
        Dim reader As XmlNodeReader = Nothing
        Try
            'Create an XmlNodeReader to read the XmlDocument.
            Dim doc As New XmlDocument()
            doc.Load(filename)
            reader = New XmlNodeReader(doc)
            
            'Parse the file and display each of the nodes.
            While reader.Read()
                Select Case reader.NodeType
                    Case XmlNodeType.Element
                        Console.Write("<{0}>", reader.Name)
                    Case XmlNodeType.Text
                        Console.Write(reader.Value)
                    Case XmlNodeType.CDATA
                        Console.Write(reader.Value)
                    Case XmlNodeType.ProcessingInstruction
                        Console.Write("<?{0} {1}?>", reader.Name, reader.Value)
                    Case XmlNodeType.Comment
                        Console.Write("<!--{0}-->", reader.Value)
                    Case XmlNodeType.XmlDeclaration
                        Console.Write("<?xml version='1.0'?>")
                    Case XmlNodeType.Document
                    Case XmlNodeType.EndElement
                        Console.Write("</{0}>", reader.Name)
                End Select
            End While
        
        Finally
            If Not (reader Is Nothing) Then
                reader.Close()
            End If
        End Try
    End Sub
End Class

En el ejemplo se usa el archivo , items.xmlcomo entrada.


<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: A</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

Comentarios

Nota

En el .NET Framework 2.0, la práctica recomendada es crear XmlReader instancias mediante la XmlReaderSettings clase y el Create método . Esto le permite aprovechar al máximo todas las nuevas características introducidas en la .NET Framework. Para obtener más información, vea la sección Comentarios de la página de XmlReader referencia.

Cuando se crea e inicializa un lector por primera vez, no hay información disponible. Debe llamar Read a para leer el primer nodo.

Se aplica a