The System.Xml.XmlTextReader Class

Supported Versions

Public Members

Overview

This class consists of a reader capable of efficiently navigating and reading through XML streams. Functionality is limited to forward-only navigation, and the methods provided by this class support only read access. Additionally, though this reader will check for well-formedness, it cannot perform any form of validation. XmlTextReader methods support the reading of node type information as well as data values.

Use this class when iterating through or retrieving data from larger documents, and when validation is not required. However, note that this class does not support files larger than 2GB. Below are three simple examples that incorporate the System.Xml.XmlTextReader class.

Example (VB.NET): How to use the XMLTextReader.MoveToContent and XMLTextReader.Read methods to read the contents of an XML document.

This first example demonstrates how the XMLTextReader.MoveToContent and XMLTextReader.Read methods can be used to iterate through the elements within an XML document.

Dim objReader As New System.Xml.XmlTextReader("c:\sample.xml")

Dim strValues As String

            While objReader.Read()

                                    objReader.MoveToContent()

                                    If objReader.NodeType = XmlNodeType.Text Then

                                    strValues &= objReader.Value & CrLf

                                    End If

            End While

                    TextBox1.Text = strValues

Example (VB.NET)

The second example samples enumerate through properties of the XmlTextReader class, and displays properties relevant to individual elements

Dim objReader As New System.Xml.XmlTextReader("c:\sample.xml")

            Dim strProperties As String

            While objReader.Read()

                                    objReader.MoveToContent()

                                    strProperties &= ".LineNumber: " & objReader.LineNumber & CrLf

                                    strProperties &= ".LocalName: " & objReader.LocalName & CrLf

                                    strProperties &= ".Name: " & objReader.Name & CrLf

                                    strProperties &= ".AttributeCount: " & objReader.AttributeCount & CrLf

                                    strProperties &= ".NodeType: " & objReader.NodeType & CrLf

                                    strProperties &= ".Prefix: " & objReader.Prefix & CrLf

                                    strProperties &= ".QuoteChar: " & objReader.QuoteChar & CrLf

                                    strProperties &= ".Value: " & objReader.Value & CrLf

                                    strProperties &= ".XmlLang: " & objReader.XmlLang & CrLf

                                    strProperties &= ".XmlSpace: " & objReader.XmlSpace & CrLf

                                    strProperties &= CrLf

            End While

                    TextBox1.Text = strProperties

Example (VB.NET)

This third example samples enumerate through properties of the XmlTextReader class, and shows property values relating to the document itself.

            Dim objReader As New System.Xml.XmlTextReader("c:\sample.xml")

            Dim strProperties As String

                    strProperties &= ".BaseURI: " & objReader.BaseURI & CrLf

            strProperties &= ".Namespaces: " & objReader.Namespaces & CrLf

            strProperties &= ".NamespaceURI: " & objReader.NamespaceURI & CrLf

            strProperties &= ".Normalization: " & objReader.Normalization & CrLf

            strProperties &= ".ReadState: " & objReader.ReadState & CrLf

            strProperties &= ".WhitespaceHandling: " & objReader.WhitespaceHandling

                    TextBox1.Text = strProperties