XmlReader.Read Method (System.Xml)

Read Method

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

XmlReader..::.Read Method

When overridden in a derived class, reads the next node from the stream.

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

Syntax

Visual Basic (Declaration)

Public MustOverride Function Read As Boolean

Visual Basic (Usage)

Dim instance As XmlReader
Dim returnValue As Boolean

returnValue = instance.Read()

public abstract bool Read()

Visual C++

public:
virtual bool Read() abstract

JScript

public abstract function Read() : boolean

Return Value

Type: System..::.Boolean
true if the next node was read successfully; false if there are no more nodes to read.

Exceptions

Exception	Condition
XmlException	An error occurred while parsing the XML.

Remarks

When an XmlReader is first created and initialized, there is no information available. You must call Read to read the first node.

This method requires at least four bytes from the data stream in order to begin parsing. If fewer than four bytes are returned and there is no more data in the stream, the method will fail. If there is more data in the stream, the method will block parsing until receipt of the fourth byte.

Examples

The following example reads an XML file and displays each of the nodes.

Visual Basic

reader.MoveToContent()
' Parse the file and display each of the nodes.
While reader.Read()
  Select Case reader.NodeType
    Case XmlNodeType.Element
      Console.Write("<{0}>", reader.Name)
    Case XmlNodeType.Text
      Console.Write(reader.Value)
    Case XmlNodeType.CDATA
      Console.Write("<![CDATA[{0}]]>", reader.Value)
    Case XmlNodeType.ProcessingInstruction
      Console.Write("<?{0} {1}?>", reader.Name, reader.Value)
    Case XmlNodeType.Comment
      Console.Write("<!--{0}-->", reader.Value)
    Case XmlNodeType.XmlDeclaration
      Console.Write("<?xml version='1.0'?>")
    Case XmlNodeType.Document
    Case XmlNodeType.DocumentType
      Console.Write("<!DOCTYPE {0} [{1}]", reader.Name, reader.Value)
    Case XmlNodeType.EntityReference
      Console.Write(reader.Name)
    Case XmlNodeType.EndElement
      Console.Write("</{0}>", reader.Name)
  End Select
End While

reader.MoveToContent();
  // Parse the file and display each of the nodes.
  while (reader.Read()) {
    switch (reader.NodeType) {
      case XmlNodeType.Element:
          Console.Write("<{0}>", reader.Name);
          break;
      case XmlNodeType.Text:
          Console.Write(reader.Value);
          break;
       case XmlNodeType.CDATA:
           Console.Write("<![CDATA[{0}]]>", reader.Value);
           break;
       case XmlNodeType.ProcessingInstruction:
           Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
           break;
       case XmlNodeType.Comment:
           Console.Write("<!--{0}-->", reader.Value);
           break;
       case XmlNodeType.XmlDeclaration:
           Console.Write("<?xml version='1.0'?>");
           break;
       case XmlNodeType.Document:
           break;
       case XmlNodeType.DocumentType:
           Console.Write("<!DOCTYPE {0} [{1}]", reader.Name, reader.Value);
           break;
       case XmlNodeType.EntityReference:
           Console.Write(reader.Name);
           break;
       case XmlNodeType.EndElement:
           Console.Write("</{0}>", reader.Name);
           break;
   } 
}

The sample uses the items.xml file.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>Test with a child element <more/> stuff</Item>
  <Item>Test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

Platforms

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.

Version Information

.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

Reference

XmlReader Class

XmlReader Members

System.Xml Namespace

Other Resources

Reading XML with the XmlReader