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XmlWriter.WriteProcessingInstruction(String, String) 方法

定義

在衍生類別中覆寫時,寫出名稱與文字之間有空白的處理指示,如下所示:<?name text?>。

public:
 abstract void WriteProcessingInstruction(System::String ^ name, System::String ^ text);
public abstract void WriteProcessingInstruction (string name, 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)

參數

name
String

處理指示的名稱。

text
String

要包含在處理指示中的文字。

例外狀況

此文字會導致非語式正確的 XML 文件。

namenullString.Empty

在呼叫 WriteStartDocument() 之後,使用這個方法來建立 XML 宣告。

在先前的非同步作業完成前呼叫了 XmlWriter 方法。 在此情況下,會擲回 InvalidOperationException 與「非同步作業已經在進行中」的訊息。

範例

下列範例會寫入代表書籍的 XML 檔案。

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

備註

這個方法可以用來撰寫 XML 宣告 (,而不是 WriteStartDocument) 。 這可能會導致編碼屬性寫入不正確。 例如,下列 C# 程式碼會導致不正確 XML 檔,因為預設編碼方式為 UTF-8。

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

如果 textnullString.Empty ,則這個方法會 ProcessingInstruction 寫入沒有資料內容的 ,例如 < ?name? > 。

如果文字包含不正確 「? > 」 序列, XmlWriter 則可以擲回 ArgumentException (物件) XmlTextWriter 或插入空格 「? >「 以避免寫入方法所 Create 建立的無效 XML (XmlWriter 物件) 。

如需這個方法的非同步版本,請參閱 WriteProcessingInstructionAsync

適用於