XmlWriter.WriteProcessingInstruction(String, String) XmlWriter.WriteProcessingInstruction(String, String) XmlWriter.WriteProcessingInstruction(String, String) XmlWriter.WriteProcessingInstruction(String, String) Method

Definition

Schreibt beim Überschreiben in einer abgeleiteten Klasse eine Verarbeitungsanweisung mit einem Leerzeichen zwischen dem Namen und dem Text wie folgt: <?name text?>.When overridden in a derived class, writes out a processing instruction with a space between the name and text as follows: <?name text?>.

public:
 abstract void WriteProcessingInstruction(System::String ^ name, System::String ^ text);
public abstract void WriteProcessingInstruction (string name, string text);
abstract member WriteProcessingInstruction : string * string -> unit
Public MustOverride Sub WriteProcessingInstruction (name As String, text As String)

Parameter

name
String String String String

Der Name der Verarbeitungsanweisung.The name of the processing instruction.

text
String String String String

Der in die Verarbeitungsanweisung einzufügende Text.The text to include in the processing instruction.

Ausnahmen

Der Text ergibt kein wohlgeformtes XML-Dokument.The text would result in a non-well formed XML document.

name ist entweder null oder String.Empty.name is either null or String.Empty.

Diese Methode wird zum Erstellen einer XML-Deklaration nach einem Aufruf von WriteStartDocument() verwendet.This method is being used to create an XML declaration after WriteStartDocument() has already been called.

Eine XmlWriter-Methode wurde aufgerufen, bevor ein vorheriger asynchroner Vorgang abgeschlossen wurde.An XmlWriter method was called before a previous asynchronous operation finished. In diesem Fall wird InvalidOperationException mit der Meldung „Es wird bereits ein asynchroner Vorgang ausgeführt“ ausgelöst.In this case, InvalidOperationException is thrown with the message "An asynchronous operation is already in progress."

Beispiele

Im folgende Beispiel schreibt eine XML-Datei, die ein Buch darstellt.The following example writes an XML file representing a book.

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

public class Sample {

  private const string filename = "sampledata.xml";

  public static void Main() {
  
     XmlWriterSettings settings = new XmlWriterSettings();
     settings.Indent = true;
     XmlWriter writer = XmlWriter.Create(filename, settings);

     // Write the Processing Instruction node.
     String PItext="type=\"text/xsl\" href=\"book.xsl\"";
     writer.WriteProcessingInstruction("xml-stylesheet", PItext);

     // Write the DocumentType node.
     writer.WriteDocType("book", null , null, "<!ENTITY h \"hardcover\">");
        
     // Write a Comment node.
     writer.WriteComment("sample XML");
    
     // Write the root element.
     writer.WriteStartElement("book");

     // Write the genre attribute.
     writer.WriteAttributeString("genre", "novel");
    
     // Write the ISBN attribute.
     writer.WriteAttributeString("ISBN", "1-8630-014");

     // Write the title.
     writer.WriteElementString("title", "The Handmaid's Tale");
              
     // Write the style element.
     writer.WriteStartElement("style");
     writer.WriteEntityRef("h");
     writer.WriteEndElement(); 

     // Write the price.
     writer.WriteElementString("price", "19.95");

     // Write CDATA.
     writer.WriteCData("Prices 15% off!!");

     // Write the close tag for the root element.
     writer.WriteEndElement();
             
     writer.WriteEndDocument();

     // Write the XML to file and close the writer.
     writer.Flush();
     writer.Close();  
  }

}
Option Strict
Option Explicit

Imports System
Imports System.IO
Imports System.Xml

Public Class Sample
    Private Const filename As String = "sampledata.xml"
    
  Public Shared Sub Main()

     Dim settings As XmlWriterSettings = new XmlWriterSettings()
     settings.Indent = true
     Dim writer As XmlWriter = XmlWriter.Create(filename, settings)
        
     ' Write the Processing Instruction node.
     Dim PItext As String = "type=""text/xsl"" href=""book.xsl"""
     writer.WriteProcessingInstruction("xml-stylesheet", PItext)
        
     'Write the DocumentType node.
     writer.WriteDocType("book", Nothing, Nothing, "<!ENTITY h ""hardcover"">")
        
     ' Write a Comment node.
     writer.WriteComment("sample XML")
        
     ' Write the root element.
     writer.WriteStartElement("book")
        
     ' Write the genre attribute
     writer.WriteAttributeString("genre", "novel")
        
     ' Write the ISBN attribute.
     writer.WriteAttributeString("ISBN", "1-8630-014")
        
     ' Write the title.
     writer.WriteElementString("title", "The Handmaid's Tale")
        
     ' Write the style element.
     writer.WriteStartElement("style")
     writer.WriteEntityRef("h")
     writer.WriteEndElement()
       
     ' Write the price.
     writer.WriteElementString("price", "19.95")
        
     ' Write CDATA.
     writer.WriteCData("Prices 15% off!!")
        
     ' Write the close tag for the root element.
     writer.WriteEndElement()
        
     writer.WriteEndDocument()
        
     ' Write the XML to file and close the writer
     writer.Flush()
     writer.Close()
        
    End Sub 'Main 
End Class 'Sample

Hinweise

Diese Methode kann zum Schreiben der XML-Deklaration verwendet werden (statt WriteStartDocument).This method can be used to write the XML declaration (rather than WriteStartDocument). Dies kann in das encoding-Attribut falsch geschriebenen führen.This could result in the encoding attribute being incorrectly written. Der folgende C#-Code würde z. B. ein ungültiges XML-Dokument führen, da die standardcodierung UTF-8 ist.For example, the following C# code would result in an invalid XML document because the default encoding is UTF-8.

XmlWriter writer = XmlWriter.Create("output.xml");  
writer.WriteProcessingInstruction("xml", "version='1.0' encoding='UTF-16'");  
writer.WriteStartElement("root");  
writer.Close();  

Wenn text ist entweder null oder String.Empty, diese Methode schreibt einen ProcessingInstruction ohne Inhalt, z. B. Daten <? Name? >.If text is either null or String.Empty, this method writes a ProcessingInstruction with no data content, for example <?name?>.

Wenn Text eine ungültige Folge von "? >", wird die XmlWriter können entweder Throw ein ArgumentException (XmlTextWriter Objekte) oder ein Leerzeichen einfügen "?If text contains an invalid sequence of "?>", the XmlWriter can either throw an ArgumentException (XmlTextWriter objects) or insert a space "? > "nicht von ungültige XML-Daten (XmlWriter Objekten von erstellt die Create Methode).>" to avoid writing invalid XML (XmlWriter objects created by the Create method).

Die asynchrone Version dieser Methode finden Sie unter WriteProcessingInstructionAsync.For the asynchronous version of this method, see WriteProcessingInstructionAsync.

Gilt für: