XmlTextWriter.WriteProcessingInstruction Method (String, String)

 

Writes out a processing instruction with a space between the name and text as follows: <?name text?>.

Namespace:   System.Xml
Assembly:  System.Xml (in System.Xml.dll)

Public Overrides Sub WriteProcessingInstruction (
	name As String,
	text As String
)

Parameters

name
Type: System.String

Name of the processing instruction.

text
Type: System.String

Text to include in the processing instruction.

Exception Condition
ArgumentException

The text would result in a non-well formed XML document.

name is either null or String.Empty.

This method is being used to create an XML declaration after WriteStartDocument has already been called.

System_CAPS_noteNote

Starting with the .NET Framework 2.0, we recommend that you create XmlWriter instances by using the XmlWriter.Create method and the XmlWriterSettings class to take advantage of new functionality.

If text is either null or String.Empty, this method writes a ProcessingInstruction with no data content, for example <?name?>.

The following example writes an XML file representing a book.

Option Explicit
Option Strict

Imports System
Imports System.IO
Imports System.Xml

Public Class Sample
    Private Shared filename As String = "sampledata.xml"
    Public Shared Sub Main()
        Dim writer As XmlTextWriter = Nothing

        writer = New XmlTextWriter(filename, Nothing)
        'Use indenting for readability.
        writer.Formatting = Formatting.Indented

        'Write the XML delcaration. 
        writer.WriteStartDocument()

        'Write the ProcessingInstruction 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 a 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()

        'Load the file into an XmlDocument to ensure well formed XML.
        Dim doc As New XmlDocument()
        'Preserve white space for readability.
        doc.PreserveWhitespace = True
        'Load the file.
        doc.Load(filename)

        'Display the XML content to the console.
        Console.Write(doc.InnerXml)
    End Sub 'Main 
End Class 'Sample

.NET Framework
Available since 1.1
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