XmlValidatingReader.HasValue Property


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

 virtual property bool HasValue { bool get(); };
public override bool HasValue { get; }
member this.HasValue : bool
Public Overrides ReadOnly Property HasValue As Boolean

Property Value


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


The following example reads in XML with various data types and displays each of the nodes.

#using <System.Xml.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
int main()
   //Create the validating reader.
   XmlTextReader^ txtreader = gcnew XmlTextReader( "book1.xml" );
   txtreader->WhitespaceHandling = WhitespaceHandling::None;
   XmlValidatingReader^ reader = gcnew XmlValidatingReader( txtreader );
   reader->ValidationType = ValidationType::None;
   //Parse the file and each node and its value.
   while ( reader->Read() )
      if ( reader->HasValue )
            Console::WriteLine( "({0})  {1}={2}", reader->NodeType, reader->Name, reader->Value );
            Console::WriteLine( "({0}) {1}", reader->NodeType, reader->Name );

   //Close the reader.

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

public class Sample

  public static void Main()

    //Create the validating reader.
    XmlTextReader txtreader = new XmlTextReader("book1.xml");
    txtreader.WhitespaceHandling = WhitespaceHandling.None;
    XmlValidatingReader reader = new XmlValidatingReader(txtreader);
    reader.ValidationType = ValidationType.None;

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

    //Close the reader.
} // End class

Imports System.IO
Imports System.Xml

public class Sample

  public shared sub  Main()
    'Create the validating reader.
    Dim txtreader as XmlTextReader = new XmlTextReader("book1.xml")
    txtreader.WhitespaceHandling = WhitespaceHandling.None
    Dim reader as XmlValidatingReader = new XmlValidatingReader(txtreader)
    reader.ValidationType = ValidationType.None

    'Parse the file and each node and its value.
    while (reader.Read())    
      if (reader.HasValue) then
        Console.WriteLine("({0})  {1}={2}", reader.NodeType, reader.Name, reader.Value)
        Console.WriteLine("({0}) {1}", reader.NodeType, reader.Name)
      end if
    end while

    'Close the reader.
  end sub
end class 



The XmlValidatingReader class is obsolete in .NET Framework 2.0. You can create a validating XmlReader instance by using the XmlReaderSettings class and the Create method. For more information, see the Remarks section of the XmlReader reference page.

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.

Applies to

See also