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XmlTextReader.HasValue Property

.NET Framework 2.0

Other Versions

Gets a value indicating whether the current node can have a Value other than String.Empty.

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

Syntax

C++

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public override bool HasValue { get; }

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/** @property */
public boolean get_HasValue ()

JScript

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public override function get HasValue () : boolean

Property Value

true if the node on which the reader is currently positioned can have a Value; otherwise, false.

Remarks

Note
In the Microsoft .NET Framework version 2.0 release, the recommended practice is to create XmlReader instances using the System.Xml.XmlReader.Create method. This allows you to take full advantage of the new features introduced in this release. For more information, see Creating XML Readers.

The following table lists node types that have a value to return.

Node type	Value
Attribute	The value of the attribute.
CDATA	The content of the CDATA section.
Comment	The content of the comment.
DocumentType	The internal subset.
ProcessingInstruction	The entire content, excluding the target.
SignificantWhitespace	The white space between markup in a mixed content model.
Text	The content of the text node.
Whitespace	The white space between markup.
XmlDeclaration	The content of the declaration.

Example

The following example displays the value for every node that can have a value.

C++

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using System;
using System.IO;
using System.Xml;

public class Sample
{

  public static void Main()
  {
    XmlTextReader reader = null;

    try
    {           
        //Load the reader with the XML file.
        reader = new XmlTextReader("book1.xml");
        reader.WhitespaceHandling = WhitespaceHandling.None;

        //Parse the file and display each node.
        while (reader.Read())
        {
           if (reader.HasValue)
             Console.WriteLine("({0})  {1}={2}", reader.NodeType, reader.Name, reader.Value);
           else
             Console.WriteLine("({0}) {1}", reader.NodeType, reader.Name);
         }           
     }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

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import System.*;
import System.IO.*;
import System.Xml.*;

public class Sample
{
    public static void main(String[] args)
    {
        XmlTextReader reader = null;

        try {
            //Load the reader with the XML file.
            reader = new XmlTextReader("book1.xml");
            reader.set_WhitespaceHandling(WhitespaceHandling.None);
            //Parse the file and display each node.
            while (reader.Read()) {
                if (reader.get_HasValue()) {
                    Console.WriteLine("({0})  {1}={2}", reader.get_NodeType(),
                        reader.get_Name(), reader.get_Value());
                }
                else {
                    Console.WriteLine("({0}) {1}", reader.get_NodeType(), 
                        reader.get_Name());
                }
            }
        } 
        finally {
            if (reader != null) {
                reader.Close();
            }
        }
    } //main
} // End class Sample

The example uses the file, book1.xml, as input.

None

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<?xml version='1.0' ?>
<!DOCTYPE book [<!ENTITY h 'hardcover'>]>
<book>
  <title>Pride And Prejudice</title>
  <misc>&h;</misc>
</book>

Platforms

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

Version Information

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

Reference

XmlTextReader Class
XmlTextReader Members
System.Xml Namespace

Other Resources

Reading XML with the XmlReader

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