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XmlTextReader.HasValue Property

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)

public override bool HasValue { get; }

Property Value

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

NoteNote:

In the .NET Framework version 2.0 release, the recommended practice is to create XmlReader instances using the 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.

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

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
#using <mscorlib.dll>
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;

int main()
{
   XmlTextReader* reader = 0;

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

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

   __finally
   {
      if (reader!=0)
         reader->Close();
   }
}

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

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0
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