XmlTextReader.Read Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Reads the next node from the stream.
public:
override bool Read();public override bool Read ();override this.Read : unit -> boolPublic Overrides Function Read () As BooleanReturns
true if the next node was read successfully; false if there are no more nodes to read.
Exceptions
An error occurred while parsing the XML.
Examples
The following example reads an XML file and displays each node.
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;
int main()
{
XmlTextReader^ reader = nullptr;
String^ filename = "items.xml";
try
{
// Load the reader with the data file and ignore all white space nodes.
reader = gcnew XmlTextReader( filename );
reader->WhitespaceHandling = WhitespaceHandling::None;
// 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;
}
}
}
finally
{
if ( reader != nullptr )
reader->Close();
}
}
using System;
using System.IO;
using System.Xml;
public class Sample {
private const String filename = "items.xml";
public static void Main() {
XmlTextReader reader = null;
try {
// Load the reader with the data file and ignore all white space nodes.
reader = new XmlTextReader(filename);
reader.WhitespaceHandling = WhitespaceHandling.None;
// 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;
}
}
}
finally {
if (reader!=null)
reader.Close();
}
}
} // End class
Option Strict
Option Explicit
Imports System.IO
Imports System.Xml
'Reads an XML document
Public Class Sample
Private Const filename As String = "items.xml"
Public Shared Sub Main()
Dim reader As XmlTextReader = Nothing
Try
' Load the reader with the data file and ignore all white space nodes.
reader = New XmlTextReader(filename)
reader.WhitespaceHandling = WhitespaceHandling.None
' 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
Finally
If Not (reader Is Nothing) Then
reader.Close()
End If
End Try
End Sub
End Class
The sample uses the file items.xml.
<?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 an char entity: A</Item>
<!-- Fourteen chars in this element.-->
<Item>1234567890ABCD</Item>
</Items>
Remarks
Note
Starting with the .NET Framework 2.0, we recommend that you create XmlReader instances by using the XmlReader.Create method to take advantage of new functionality.
When a reader 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.
