The System.Xml.Serialization.XmlArrayItemAttribute belongs to a family of attributes that controls how the System.Xml.Serialization.XmlSerializer serializes or deserializes an object. For a complete list of similar attributes, see Attributes That Control XML Serialization.

You can apply the System.Xml.Serialization.XmlArrayItemAttribute to any public read/write member that returns an array, or provides access to one. For example, a field that returns an array of objects, a collection, an ArrayList, or any class that implements the IEnumerable interface.

The System.Xml.Serialization.XmlArrayItemAttribute supports polymorphism--in other words, it allows the System.Xml.Serialization.XmlSerializer to add derived objects to an array. For example, suppose a class named Mammal is derived from a base class named Animal. Further suppose that a class named MyAnimals contains a field that returns an array of Animal objects. To allow the System.Xml.Serialization.XmlSerializer to serialize both the Animal and Mammal type, apply the System.Xml.Serialization.XmlArrayItemAttribute to the field twice, each time specifying one of the two acceptable types.

For more information about using attributes, see Extending Metadata Using Attributes.