XmlTextReader.Read-Methode
Liest den nächsten Knoten aus dem Stream.
Namespace: System.Xml
Assembly: System.Xml (in system.xml.dll)
Syntax
'Declaration
Public Overrides Function Read As Boolean
'Usage
Dim instance As XmlTextReader
Dim returnValue As Boolean
returnValue = instance.Read
public override bool Read ()
public:
virtual bool Read () override
public boolean Read ()
public override function Read () : boolean
Rückgabewert
true, wenn der nächste Knoten erfolgreich gelesen wurde, false, wenn keine weiteren zu lesenden Knoten vorhanden sind.
Ausnahmen
| Ausnahmetyp | Bedingung |
|---|---|
Beim Analysieren der XML ist ein Fehler aufgetreten. |
Hinweise
Hinweis
Die empfohlene Vorgehensweise für die Version Microsoft .NET Framework, Version 2.0 besteht darin, mithilfe der System.Xml.XmlReader.Create-Methode XmlReader-Instanzen zu erstellen. So können Sie die neuen Features dieser Version in vollem Umfang nutzen. Weitere Informationen finden Sie unter Erstellen von XML-Readern.
Nachdem ein Reader das erste Mal erstellt und initialisiert wurde, stehen keine Informationen zur Verfügung. Zum Lesen des ersten Knotens muss Read aufgerufen werden.
Beispiel
Im folgenden Beispiel wird eine XML-Datei gelesen, und alle Knoten werden angezeigt.
Option Strict
Option Explicit
Imports System
Imports System.IO
Imports System.Xml
'Reads an XML document
Public Class Sample
Private Const filename As String = "items.xml"
Public Shared Sub Main()
Dim reader As XmlTextReader = Nothing
Try
' Load the reader with the data file and ignore all white space nodes.
reader = New XmlTextReader(filename)
reader.WhitespaceHandling = WhitespaceHandling.None
' 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("<![CDATA[{0}]]>", 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.DocumentType
Console.Write("<!DOCTYPE {0} [{1}]", reader.Name, reader.Value)
Case XmlNodeType.EntityReference
Console.Write(reader.Name)
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 'Main
End Class 'Sample
using System;
using System.IO;
using System.Xml;
public class Sample {
private const String filename = "items.xml";
public static void Main() {
XmlTextReader reader = null;
try {
// Load the reader with the data file and ignore all white space nodes.
reader = new XmlTextReader(filename);
reader.WhitespaceHandling = WhitespaceHandling.None;
// 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("<![CDATA[{0}]]>", 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.DocumentType:
Console.Write("<!DOCTYPE {0} [{1}]", reader.Name, reader.Value);
break;
case XmlNodeType.EntityReference:
Console.Write(reader.Name);
break;
case XmlNodeType.EndElement:
Console.Write("</{0}>", reader.Name);
break;
}
}
}
finally {
if (reader!=null)
reader.Close();
}
}
} // End class
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;
int main()
{
XmlTextReader^ reader = nullptr;
String^ filename = "items.xml";
try
{
// Load the reader with the data file and ignore all white space nodes.
reader = gcnew XmlTextReader( filename );
reader->WhitespaceHandling = WhitespaceHandling::None;
// 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( "<![CDATA[{0}]]>", 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::DocumentType:
Console::Write( "<!DOCTYPE {0} [{1}]", reader->Name, reader->Value );
break;
case XmlNodeType::EntityReference:
Console::Write( reader->Name );
break;
case XmlNodeType::EndElement:
Console::Write( "</{0}>", reader->Name );
break;
}
}
}
finally
{
if ( reader != nullptr )
reader->Close();
}
}
import System.*;
import System.IO.*;
import System.Xml.*;
public class Sample
{
private static String fileName = "items.xml";
public static void main(String[] args)
{
XmlTextReader reader = null;
try {
// Load the reader with the data file and ignore
//all white space nodes.
reader = new XmlTextReader(fileName);
reader.set_WhitespaceHandling(WhitespaceHandling.None);
// Parse the file and display each of the nodes.
while(reader.Read()) {
switch(reader.get_NodeType() ) {
case XmlNodeType.Element :
Console.Write("<{0}>", reader.get_Name());
break;
case XmlNodeType.Text :
Console.Write(reader.get_Value());
break;
case XmlNodeType.CDATA :
Console.Write("<![CDATA[{0}]]>", reader.get_Value());
break;
case XmlNodeType.ProcessingInstruction :
Console.Write("<?{0} {1}?>", reader.get_Name(),
reader.get_Value());
break;
case XmlNodeType.Comment :
Console.Write("<!--{0}-->", reader.get_Value());
break;
case XmlNodeType.XmlDeclaration :
Console.Write("<?xml version='1.0'?>");
break;
case XmlNodeType.Document :
break;
case XmlNodeType.DocumentType :
Console.Write("<!DOCTYPE {0} [{1}]", reader.get_Name(),
reader.get_Value());
break;
case XmlNodeType.EntityReference :
Console.Write(reader.get_Name());
break;
case XmlNodeType.EndElement :
Console.Write("</{0}>", reader.get_Name());
break;
}
}
}
finally {
if (reader != null) {
reader.Close();
}
}
} //main
} // End class Sample
Im Beispiel wird die Datei items.xml verwendet.
<?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 an char entity: A</Item>
<!-- Fourteen chars in this element.-->
<Item>1234567890ABCD</Item>
</Items>
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0, 1.0
Siehe auch
Referenz
XmlTextReader-Klasse
XmlTextReader-Member
System.Xml-Namespace
EntityHandling-Enumeration