XmlWriter.WriteDocType(String, String, String, String) 方法

定义

命名空间:

System.Xml

程序集:

System.Xml.ReaderWriter.dll

程序集:

System.Xml.dll

程序集:

netstandard.dll

当在派生类中被重写时，写出具有指定名称和可选属性的 DOCTYPE 声明。

public:
 abstract void WriteDocType(System::String ^ name, System::String ^ pubid, System::String ^ sysid, System::String ^ subset);

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

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

abstract member WriteDocType : string * string * string * string -> unit

Public MustOverride Sub WriteDocType (name As String, pubid As String, sysid As String, subset As String)

参数

name

String

DOCTYPE 的名称。 它必须是非空的。

pubid

String

如果非 null，则它还编写 PUBLIC "pubid" "sysid"，这里的 pubid 和 sysid 用给定参数的值替换。

sysid

String

如果 pubid 为 null 而 sysid 非 null，则它编写 SYSTEM "sysid"，这里的 sysid 用此参数的值替换。

subset

String

如果非 null，则它写入 [subset]，其中 subset 替换为此参数的值。

例外

InvalidOperationException

在序言码外部（根元素之后）调用了此方法。

• 或 -

在上一次异步操作完成之前调用了 XmlWriter 方法。 在此情况下，会引发 InvalidOperationException 并显示消息“异步操作已在进行中。”

ArgumentException

name 的值将导致无效的 XML。

示例

以下示例编写一个表示书籍的 XML 文件。

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

注解

此方法不会检查中 pubid是否有无效字符或 sysid subset。 它还不检查内部子集的格式正确。

重要

不 XmlWriter 验证传递给 WriteDocType 该方法的数据。 不应将任意数据传递给此方法。

有关此方法的异步版本，请参阅 WriteDocTypeAsync。