This documentation is archived and is not being maintained.

XmlValidatingReader.HasValue Property

Gets a value indicating whether the current node can have a Value.

[Visual Basic]
Overrides Public ReadOnly Property HasValue As Boolean
public override bool HasValue {get;}
public: __property bool get_HasValue();
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.


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.


[Visual Basic, C#, C++] The following example reads in XML with various data types and displays each of the nodes.

[Visual Basic] 
Imports System
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 

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

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

int main()

   //Create the validating reader.
   XmlTextReader* txtreader = new XmlTextReader(S"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(S"({0})  {1}={2}", __box(reader->NodeType), reader->Name, reader->Value);
         Console::WriteLine(S"({0}) {1}", __box(reader->NodeType), reader->Name);


   //Close the reader.


[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

XmlValidatingReader Class | XmlValidatingReader Members | System.Xml Namespace