XmlWriter.WriteComment(String) Metoda

Definice

Při přepsání v odvozené třídě zapíše komentář < !--...-- > obsahující zadaný text.When overridden in a derived class, writes out a comment <!--...--> containing the specified text.

public:
 abstract void WriteComment(System::String ^ text);
public abstract void WriteComment (string text);
public abstract void WriteComment (string? text);
abstract member WriteComment : string -> unit
Public MustOverride Sub WriteComment (text As String)

Parametry

text
String

Text, který se má umístit do komentářeText to place inside the comment.

Výjimky

Text by měl být v dokumentu XML, který není správně vytvořen.The text would result in a non-well-formed XML document.

XmlWriterMetoda byla volána před dokončením předchozí asynchronní operace.An XmlWriter method was called before a previous asynchronous operation finished. V tomto případě InvalidOperationException je vyvolána se zprávou "asynchronní operace již probíhá".In this case, InvalidOperationException is thrown with the message "An asynchronous operation is already in progress."

Příklady

Následující příklad zapisuje soubor XML reprezentující knihu.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.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
End Class

Poznámky

Pokud text buď je null String.Empty , nebo, tato metoda zapisuje komentář bez datového obsahu, například <!----> .If text is either null or String.Empty, this method writes a comment with no data content, for example <!---->.

Pokud text obsahuje neplatnou sekvenci dvou pomlček "--", XmlWriter může buď vyvolat ArgumentException ( XmlTextWriter objekty), nebo vložit mezeru mezi pomlčky "--", aby text byl platným komentářem XML ( XmlWriter objekty vytvořené Create metodou).If text contains an invalid sequence of two dashes "--" the XmlWriter can either throw an ArgumentException (XmlTextWriter objects) or insert a space between the dashes "- -" so that the text is a valid XML comment (XmlWriter objects created by the Create method).

Asynchronní verze této metody naleznete v tématu WriteCommentAsync .For the asynchronous version of this method, see WriteCommentAsync.

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