XmlReader.ReadInnerXml Method

Definition

Namespace:

System.Xml

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlReader.cs

When overridden in a derived class, reads all the content, including markup, as a string.

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

public virtual string ReadInnerXml ();

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

Public Overridable Function ReadInnerXml () As String

Returns

String

All the XML content, including markup, in the current node. If the current node has no children, an empty string is returned.

If the current node is neither an element nor attribute, an empty string is returned.

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 returns all the content of the current node including the markup. The current node (start tag) and corresponding end node (end tag) are not returned. For example, if you had the following:

<node>
 this <child id="123"/>
</node>

ReadInnerXml returns this <child id="123"/>

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>	text1	On the item2 start tag.
Attribute	On the attr1 attribute node.	<item attr1="val1" attr2="val2">text</item>	val1	Remains on the attr1 attribute node.

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

This method checks for well-formed XML. If ReadInnerXml 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.

For the asynchronous version of this method, see ReadInnerXmlAsync.