public void SerializeObject(string filename)
{
string path = @"..\..\..\TmpFile";
string file = Path.Combine(path, filename);
/* Each overridden field, property, or type requires an XmlAttributes object. */
XmlAttributes attrs = new XmlAttributes();
/* Create an XmlElementAttribute to override the field that returns Instrument objects.
* The overridden field returns Brass objects instead. */
XmlElementAttribute attr = new XmlElementAttribute();
attr.ElementName = "Brass";
attr.Type = typeof(Brass);
// Add the element to the collection of elements.
attrs.XmlElements.Add(attr);
// Create the XmlAttributeOverrides object.
XmlAttributeOverrides attrOverrides = new XmlAttributeOverrides();
/* Add the type of the class that contains the overridden member and the XmlAttributes
* to override it with to the XmlAttributeOverrides object. */
attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);
// Writing the file requires a TextWriter.
using (TextWriter writer = new StreamWriter(file))
{
// Create the XmlSerializer using the XmlAttributeOverrides.
XmlSerializer s = new XmlSerializer(typeof(Orchestra), attrOverrides);
// Create the object that will be serialized.
Orchestra band = new Orchestra();
Instrument[] myInstruments =
{
// Create an object of the derived type.
new Brass()
{
Name = "Trumpet"
, IsValved = true
}
/*
* , new Instrument()
* {
* Name = "Violin"
* }
*/
};
band.Instruments = myInstruments;
// Serialize the object.
s.Serialize(writer, band);
}
}
public void DeserializeObject(string filename)
{
string path = @"..\..\..\TmpFile";
string file = Path.Combine(path, filename);
XmlAttributes attrs = new XmlAttributes();
// Create an XmlElementAttribute to override the Instrument.
XmlElementAttribute attr = new XmlElementAttribute();
attr.ElementName = "Brass";
attr.Type = typeof(Brass);
// Add the XmlElementAttribute to the collection of objects.
attrs.XmlElements.Add(attr);
XmlAttributeOverrides attrOverrides = new XmlAttributeOverrides();
attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);
using (FileStream fs = new FileStream(file, FileMode.Open))
{
// Create the XmlSerializer using the XmlAttributeOverrides.
XmlSerializer s = new XmlSerializer(typeof(Orchestra), attrOverrides);
Orchestra band = (Orchestra)s.Deserialize(fs);
Console.WriteLine("Brass:");
/* The difference between deserializing the overridden XML document and serializing it is this:
* To read the derived object values, you must declare an object of the derived type (Brass),
* and cast the Instrument instance to it. */
Brass b;
foreach (Instrument i in band.Instruments)
{
b = (Brass)i;
Console.WriteLine(b.Name + "\n" + b.IsValved);
}
}
}
