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XmlWriter.WriteAttributes Method

When overridden in a derived class, writes out all the attributes found at the current position in the XmlReader.

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

public virtual void WriteAttributes(
	XmlReader reader,
	bool defattr
)

Parameters

reader
Type: System.Xml.XmlReader

The XmlReader from which to copy the attributes.

defattr
Type: System.Boolean

true to copy the default attributes from the XmlReader; otherwise, false.

ExceptionCondition
ArgumentNullException

reader is null.

XmlException

The reader is not positioned on an element, attribute or XmlDeclaration node.

InvalidOperationException

An XmlWriter method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message “An asynchronous operation is already in progress.”

If the reader is positioned on an element node WriteAttributes copies all the contained attributes. If the reader is positioned on an attribute node, this method writes the current attribute, then the rest of the attributes until the element closing tag. If the reader is positioned on an XmlDeclaration node, this method writes all the attributes in the declaration. If the reader is positioned on any other node type this method throws an XmlException.

If this method is called using XmlValidatingReader, to ensure well-formed XML any content (which has been expanded from the entities) that could result in an invalid document is replaced when written. For example, if an attribute includes an > entity that has been expanded, to ensure a well-formed document the expanded > is replaced when written out with >.

For the asynchronous version of this method, see WriteAttributesAsync.

The following example copies all the elements to the output, changes the tag names to upper case, and copies all the attributes unchanged.

using System;
using System.IO;
using System.Xml;

public class Sample {

  public static void Main() {

    XmlReader reader = XmlReader.Create("test1.xml");
    XmlWriterSettings settings = new XmlWriterSettings();
    settings.Indent = true;
    XmlWriter writer = XmlWriter.Create(Console.Out);

    while (reader.Read()) {
      if (reader.NodeType == XmlNodeType.Element) {
        writer.WriteStartElement(reader.Name.ToUpper());
        writer.WriteAttributes(reader, false);
        if (reader.IsEmptyElement) writer.WriteEndElement();
      }
      else if (reader.NodeType == XmlNodeType.EndElement) {
        writer.WriteEndElement();
      }
    }
    writer.Close();
    reader.Close();
  }
}

The example uses the file, test1.xml, as input.

<test a="1" b="2">
    <item c="3" d="4" e="5" f="6"/>
</test>

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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