XmlDataDocument does not support creating entity references. If the data source contains entity references, you must create an XmlValidatingReader with the EntityHandling property set to EntityHandling.ExpandEntities (this is the default behavior) and pass the XmlValidatingReader to the Load method. If you do not use an XmlValidatingReader, the Load method throws an exception.

The Load method always preserves significant white space. The PreserveWhitespace property determines whether or not white space is preserved. The default is false, white space is not preserved.

If the reader is in the initial state (that is, ReadState=ReadState.Initial), Load consumes the entire contents of the reader and builds the DOM from what it finds.

If the reader is already positioned on some node at depth "n", then this method loads that node and all subsequent siblings up to the end tag that closes depth "n". This has the following results.

If the current node and its following siblings look similar to the following:

<!--comment--><element1>one</element1><element2>two</element2>

Load throws an exception, because a document cannot have two root-level elements. If the current node and its following siblings look similar to the following:

<!--comment--><?process
    instruction?><!--comment--></endtag>

Load will succeed; however, you will have an incomplete DOM tree, because there is no root-level element. You have to add a root-level element before you save the document; otherwise, the Save method throws an exception.

If the reader is positioned on a leaf node that is invalid for the root level of a document (for example, a white space or attribute node), the reader continues to read until it is positioned on a node that can be used for the root. The document begins loading at this point.

The following example modifies the price of a book using the DataSet methods.

Imports System
Imports System.Data
Imports System.Xml

public class Sample

  public shared sub Main()

      'Create an XmlDataDocument.
      Dim doc as XmlDataDocument = new XmlDataDocument()

      'Load the schema.
      doc.DataSet.ReadXmlSchema("store.xsd") 

      'Load the XML data.
      Dim reader as XmlTextReader = new XmlTextReader("2books.xml")
      reader.MoveToContent() 'Moves the reader to the root node.
      doc.Load(reader)

     'Change the price on the first book imports the DataSet methods.
     Dim books as DataTable = doc.DataSet.Tables.Item("book")
     books.Rows.Item(0).Item("price") = "12.95"

     Console.WriteLine("Display the modified XML data...")
     doc.Save(Console.Out)

  end sub
end class

using System;
using System.Data;
using System.Xml;
public class Sample {
    public static void Main() {
        // Create an XmlDataDocument.
        XmlDataDocument doc = new XmlDataDocument();

        // Load the schema file.
        doc.DataSet.ReadXmlSchema("store.xsd");

        // Load the XML data.
        XmlTextReader reader = new XmlTextReader("2books.xml");
        reader.MoveToContent(); // Moves the reader to the root node.
        doc.Load(reader);

        // Update the price on the first book using the DataSet methods.
        DataTable books = doc.DataSet.Tables["book"];
        books.Rows[0]["price"] = "12.95";

        Console.WriteLine("Display the modified XML data...");
        doc.Save(Console.Out);
    }
} // End class

#using <System.dll>
#using <System.Data.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Data;
using namespace System::Xml;
int main()
{
   // Create an XmlDataDocument.
   XmlDataDocument^ doc = gcnew XmlDataDocument;

   // Load the schema file.
   doc->DataSet->ReadXmlSchema( "store.xsd" );

   // Load the XML data.
   XmlTextReader^ reader = gcnew XmlTextReader( "2books.xml" );
   reader->MoveToContent(); // Moves the reader to the root node.
   doc->Load( reader );

   // Update the price on the first book using the DataSet methods.
   DataTable^ books = doc->DataSet->Tables["book"];
   books->Rows[0]["price"] = "12.95";
   Console::WriteLine( "Display the modified XML data..." );
   doc->Save( Console::Out );
}

The example uses the following two input files.

2books.xml

<!--sample XML fragment-->
<bookstore>
  <book genre='novel' ISBN='10-861003-324'>
    <title>The Handmaid's Tale</title>
    <price>19.95</price>
  </book>
  <book genre='novel' ISBN='1-861001-57-5'>
    <title>Pride And Prejudice</title>
    <price>24.95</price>
  </book>
</bookstore>

store.xsd

<xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema">

 <xsd:element name="bookstore" type="bookstoreType"/>

 <xsd:complexType name="bookstoreType">
  <xsd:sequence maxOccurs="unbounded">
   <xsd:element name="book"  type="bookType"/>
  </xsd:sequence>
 </xsd:complexType>

 <xsd:complexType name="bookType">
  <xsd:sequence>
   <xsd:element name="title" type="xsd:string"/>
   <xsd:element name="author" type="authorName"/>
   <xsd:element name="price"  type="xsd:decimal"/>
  </xsd:sequence>
  <xsd:attribute name="genre" type="xsd:string"/>
 </xsd:complexType>

 <xsd:complexType name="authorName">
  <xsd:sequence>
   <xsd:element name="first-name"  type="xsd:string"/>
   <xsd:element name="last-name" type="xsd:string"/>
  </xsd:sequence>
 </xsd:complexType>

</xsd:schema>

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

.NET Framework

Reference