XmlReader.ReadToDescendant Method (String)

 
System_CAPS_noteNote

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Advances the XmlReader to the next descendant element with the specified qualified name.

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

public virtual bool ReadToDescendant(
	string name
)

Parameters

name
Type: System.String

The qualified name of the element you wish to move to.

Return Value

Type: System.Boolean

true if a matching descendant element is found; otherwise false. If a matching child element is not found, the XmlReader is positioned on the end tag (NodeType is XmlNodeType.EndElement) of the element.

If the XmlReader is not positioned on an element when ReadToDescendant was called, this method returns false and the position of the XmlReader is not changed.

Exception Condition
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.”

ArgumentException

The parameter is an empty string.

The following example parses the second book node.

using (XmlReader reader = XmlReader.Create("2books.xml")) {

  // Move the reader to the second book node.
  reader.MoveToContent(); 
  reader.ReadToDescendant("book");
  reader.Skip(); //Skip the first book.

  // Parse the file starting with the second book node.
  do {
     switch (reader.NodeType) {
        case XmlNodeType.Element:
           Console.Write("<{0}", reader.Name);
           while (reader.MoveToNextAttribute()) {
               Console.Write(" {0}='{1}'", reader.Name, reader.Value);
           }
           Console.Write(">");
           break;
        case XmlNodeType.Text:
           Console.Write(reader.Value);
           break;
        case XmlNodeType.EndElement:
           Console.Write("</{0}>", reader.Name);
           break;
     }       
  }  while (reader.Read());    

}

The example uses the file, 2books.xml, 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>

Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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