XmlWriter.WriteDocType(String, String, String, String) Method

Definition

Namespace:

System.Xml

Assemblies:

netstandard.dll, System.Xml.ReaderWriter.dll

Source:

XmlWriter.cs

When overridden in a derived class, writes the DOCTYPE declaration with the specified name and optional attributes.

C#

public abstract void WriteDocType(string name, string? pubid, string? sysid, string? subset);

Parameters

name

String

The name of the DOCTYPE. This must be non-empty.

pubid

String

If non-null it also writes PUBLIC "pubid" "sysid" where pubid and sysid are replaced with the value of the given arguments.

sysid

String

If pubid is null and sysid is non-null it writes SYSTEM "sysid" where sysid is replaced with the value of this argument.

subset

String

If non-null it writes [subset] where subset is replaced with the value of this argument.

Exceptions

InvalidOperationException

This method was called outside the prolog (after the root element).

-or-

An XmlWriter method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message "An asynchronous operation is already in progress."

ArgumentException

The value for name would result in invalid XML.

Examples

The following example writes an XML file representing a book.

C#

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();
  }
}

Remarks

This method does not check for invalid characters in pubid, sysid or subset. It also does not check that the internal subset is well-formed.

Важно

The XmlWriter does not validate the data that is passed to the WriteDocType method. You should not pass arbitrary data to this method.

For the asynchronous version of this method, see WriteDocTypeAsync.

Applies to