XmlReader.ReadOuterXml Method

Definition

Namespace:

System.Xml

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlReader.cs

When overridden in a derived class, reads the content, including markup, representing this node and all its children.

public:
 virtual System::String ^ ReadOuterXml();

public virtual string ReadOuterXml ();

abstract member ReadOuterXml : unit -> string
override this.ReadOuterXml : unit -> string

Public Overridable Function ReadOuterXml () As String

Returns

String

If the reader is positioned on an element or an attribute node, this method returns all the XML content, including markup, of the current node and all its children; otherwise, it returns an empty string.

Exceptions

XmlException

The XML was not well-formed, or an error occurred while parsing the XML.

InvalidOperationException

An XmlReader 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."

Examples

The following example compares the ReadInnerXml and ReadOuterXml methods.

// Load the file and ignore all white space.
XmlReaderSettings settings = new XmlReaderSettings();
settings.IgnoreWhitespace = true;
using (XmlReader reader = XmlReader.Create("2books.xml")) {

  // Moves the reader to the root element.
  reader.MoveToContent();

  // Moves to book node.
  reader.Read();

  // Note that ReadInnerXml only returns the markup of the node's children
  // so the book's attributes are not returned.
  Console.WriteLine("Read the first book using ReadInnerXml...");
  Console.WriteLine(reader.ReadInnerXml());

  // ReadOuterXml returns the markup for the current node and its children
  // so the book's attributes are also returned.
  Console.WriteLine("Read the second book using ReadOuterXml...");
  Console.WriteLine(reader.ReadOuterXml());
}

' Load the file and ignore all white space.
Dim settings As New XmlReaderSettings()
settings.IgnoreWhitespace = True
Using reader As XmlReader = XmlReader.Create("2books.xml")

  ' Moves the reader to the root element.
  reader.MoveToContent()
                
  ' Moves to book node.
  reader.Read()
                
  ' Note that ReadInnerXml only returns the markup of the node's children
  ' so the book's attributes are not returned.
  Console.WriteLine("Read the first book using ReadInnerXml...")
  Console.WriteLine(reader.ReadInnerXml())
                
  ' ReadOuterXml returns the markup for the current node and its children
  ' so the book's attributes are also returned.
  Console.WriteLine("Read the second book using ReadOuterXml...")
  Console.WriteLine(reader.ReadOuterXml())

End Using

The example uses 2books.xml file as input.

<!--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>

Remarks

This method is similar to ReadInnerXml except it also returns the start and end tags.

This method handles element and attribute nodes in the following manner:

Node type	Position before the call	XML fragment	Return value	Position After the Call
Element	On the item1 start tag.	<item1>text1</item1><item2>text2</item2>	<item1>text1</item1>	On the item2 start tag.
Attribute	On the attr1 attribute node.	<item attr1="val1" attr2="val2">text</item>	attr1="val1"	Remains on the attr1 attribute node.

If the reader is positioned on a leaf node, calling ReadOuterXml is equivalent to calling Read. The method returns String.Empty (except for attribute nodes, in which case the attribute markup is returned).

This method checks for well-formed XML. If ReadOuterXml is called from an XmlValidatingReader, this method also validates the content returned

As implemented in the XmlNodeReader, XmlTextReader and XmlValidatingReader classes the ReadOuterXml method is namespace aware. Given the following XML text <A xmlns:S="urn:1"><S:B>hello</S:B></A>, if the reader were positioned on the S:B start tag, ReadOuterXml returns <S:B xmlns:S="urn:1">hello<S:B/>.

For the asynchronous version of this method, see ReadOuterXmlAsync.