XmlTextReader.WhitespaceHandling Proprietà

Definizione

Spazio dei nomi:

System.Xml

Assembly:

System.Xml.ReaderWriter.dll

Origine:

XmlTextReader.cs

Ottiene o imposta un valore che specifica come viene gestito lo spazio vuoto.

public:
 property System::Xml::WhitespaceHandling WhitespaceHandling { System::Xml::WhitespaceHandling get(); void set(System::Xml::WhitespaceHandling value); };

public System.Xml.WhitespaceHandling WhitespaceHandling { get; set; }

member this.WhitespaceHandling : System.Xml.WhitespaceHandling with get, set

Public Property WhitespaceHandling As WhitespaceHandling

Valore della proprietà

WhitespaceHandling

Uno dei valori di WhitespaceHandling. Il valore predefinito è WhitespaceHandling.All (restituisce i nodi Whitespace e SignificantWhitespace).

Eccezioni

ArgumentOutOfRangeException

È stato specificato un valore non valido.

InvalidOperationException

Impostare questa proprietà quando il visualizzatore è chiuso (ReadState è ReadState.Closed).

Esempio

Nell'esempio seguente viene letto un frammento XML.

#using <System.Xml.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
void ReadXML( XmlParserContext^ context, String^ xmlFrag, WhitespaceHandling ws )
{
   
   //Create the reader and specify the WhitespaceHandling setting.
   XmlTextReader^ reader = gcnew XmlTextReader( xmlFrag,XmlNodeType::Element,context );
   reader->WhitespaceHandling = ws;
   
   //Parse the XML and display each of the nodes.
   while ( reader->Read() )
   {
      switch ( reader->NodeType )
      {
         case XmlNodeType::Element:
            Console::WriteLine( "{0}: <{1}>", reader->NodeType, reader->Name );
            break;

         case XmlNodeType::Text:
            Console::WriteLine( "{0}: {1}", reader->NodeType, reader->Value );
            break;

         case XmlNodeType::EndElement:
            Console::WriteLine( "{0}: </{1}>", reader->NodeType, reader->Name );
            break;

         case XmlNodeType::Whitespace:
            Console::WriteLine( "{0}:", reader->NodeType );
            break;

         case XmlNodeType::SignificantWhitespace:
            Console::WriteLine( "{0}:", reader->NodeType );
            break;
      }
   }

   
   //Close the reader.
   reader->Close();
}

int main()
{
   
   //Create the XML fragment to be parsed.
   String^ xmlFrag = "<book> "
   "  <title>Pride And Prejudice</title>"
   "  <genre>novel</genre>"
   "</book>";
   
   //Create the XmlNamespaceManager.
   NameTable^ nt = gcnew NameTable;
   XmlNamespaceManager^ nsmgr = gcnew XmlNamespaceManager( nt );
   
   //Create the XmlParserContext.
   XmlParserContext^ context = gcnew XmlParserContext( nullptr,nsmgr,nullptr,XmlSpace::Default );
   Console::WriteLine( "Read the XML and ignore all white space..." );
   ReadXML( context, xmlFrag, WhitespaceHandling::None );
   Console::WriteLine( "\r\nRead the XML including white space nodes..." );
   ReadXML( context, xmlFrag, WhitespaceHandling::All );
}

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

public class Sample
{
  public static void Main(){

    //Create the XML fragment to be parsed.
    string xmlFrag ="<book> " +
                    "  <title>Pride And Prejudice</title>" +
                    "  <genre>novel</genre>" +
                    "</book>";

    //Create the XmlNamespaceManager.
    NameTable nt = new NameTable();
    XmlNamespaceManager nsmgr = new XmlNamespaceManager(nt);

    //Create the XmlParserContext.
    XmlParserContext context = new XmlParserContext(null, nsmgr, null, XmlSpace.Default);

    Console.WriteLine("Read the XML and ignore all white space...");
    ReadXML(context, xmlFrag, WhitespaceHandling.None);

    Console.WriteLine("\r\nRead the XML including white space nodes...");
    ReadXML(context, xmlFrag, WhitespaceHandling.All);
  }

  public static void ReadXML(XmlParserContext context, string xmlFrag, WhitespaceHandling ws){

    //Create the reader and specify the WhitespaceHandling setting.
    XmlTextReader reader = new XmlTextReader(xmlFrag, XmlNodeType.Element, context);
    reader.WhitespaceHandling = ws;

      //Parse the XML and display each of the nodes.
      while (reader.Read())
      {
         switch (reader.NodeType)
         {
           case XmlNodeType.Element:
             Console.WriteLine("{0}: <{1}>", reader.NodeType, reader.Name);
             break;
           case XmlNodeType.Text:
             Console.WriteLine("{0}: {1}", reader.NodeType, reader.Value);
             break;
           case XmlNodeType.EndElement:
             Console.WriteLine("{0}: </{1}>", reader.NodeType, reader.Name);
             break;
           case XmlNodeType.Whitespace:
             Console.WriteLine("{0}:", reader.NodeType);
             break;
           case XmlNodeType.SignificantWhitespace:
             Console.WriteLine("{0}:", reader.NodeType);
             break;
         }
      }

    //Close the reader.
    reader.Close();
  }
} // End class

Imports System.IO
Imports System.Xml

public class Sample 

  public shared sub Main()

    'Create the XML fragment to be parsed.
    Dim xmlFrag as string ="<book> " & _
                           "  <title>Pride And Prejudice</title>" & _
                           "  <genre>novel</genre>" & _
                           "</book>" 

    'Create the XmlNamespaceManager.
    Dim nt as NameTable = new NameTable()
    Dim nsmgr as XmlNamespaceManager = new XmlNamespaceManager(nt)

    'Create the XmlParserContext.
    Dim context as XmlParserContext = new XmlParserContext(nothing, nsmgr, nothing, XmlSpace.Default)

    Console.WriteLine("Read the XML and ignore all white space...")
    ReadXML(context, xmlFrag, WhitespaceHandling.None)

    Console.WriteLine()
    Console.WriteLine("Read the XML including white space nodes...")
    ReadXML(context, xmlFrag, WhitespaceHandling.All)
  end sub
  
  public shared sub ReadXML(context as XmlParserContext, xmlFrag as string, ws as WhitespaceHandling)

    'Create the reader and specify the WhitespaceHandling setting.
    Dim reader as XmlTextReader = new XmlTextReader(xmlFrag, XmlNodeType.Element, context)
    reader.WhitespaceHandling = ws

      'Parse the XML and display each of the nodes.
      while (reader.Read())
         select case reader.NodeType
           case XmlNodeType.Element:
             Console.WriteLine("{0}: <{1}>", reader.NodeType, reader.Name)
           case XmlNodeType.Text:
             Console.WriteLine("{0}: {1}", reader.NodeType, reader.Value)
           case XmlNodeType.EndElement:
             Console.WriteLine("{0}: </{1}>", reader.NodeType, reader.Name)
           case XmlNodeType.Whitespace:
             Console.WriteLine("{0}:", reader.NodeType)
           case XmlNodeType.SignificantWhitespace:
             Console.WriteLine("{0}:", reader.NodeType)
         end select       
      end while           
  
    'Close the reader.
    reader.Close()     
  
  end sub
end class

Commenti

Nota

A partire da .NET Framework 2.0, è consigliabile creare XmlReader istanze usando il XmlReader.Create metodo per sfruttare nuove funzionalità.

Questa proprietà può essere modificata in qualsiasi momento e ha effetto sull'operazione di lettura successiva.

Poiché le XmlTextReader informazioni DTD non sono disponibili, SignificantWhitespace i nodi vengono restituiti solo all'interno di un xml:space='preserve' ambito.

Vedi anche

• XmlReader