C# 4 and .NET 4

938 ❘ ChaPTer 33 mAnipulAtinG xml
Product newPd;
//new filestream to open serialized object
FileStream f = new FileStream("serialprod.xml", FileMode.Open);
Once again, you create a new XmlSerializer, passing in the type information of Product. You can then
make the call to the Deserialize() method. Note that you still need to do an explicit cast when you create
the newPd object. At this point, newPd is in exactly the same state that pd was:
//new serializer
XmlSerializer newSr = new XmlSerializer(typeof(Product));
//deserialize the object
newPd = (Product)newSr.Deserialize(f);
f.Close();
MessageBox.Show(newPd.ToString());
}
code snippet frmSerial.cs
The message box should show you the product ID, product name, and the unit price of the object you just
deserialized. This comes from the ToString() override that you implemented in the Product class.
What about situations where you have derived classes and possibly properties that return an array
XmlSerializer has that covered as well. Here’s a slightly more complex example that deals with these issues.
First, you define three new classes, Product, BookProduct (derived from Product), and Inventory (which
contains both of the other classes). Notice that once again you have overridden the ToString() method.
This time you’re just going to list the items in the Inventory class:
public class BookProduct: Product
{
private string isbnNum;
public BookProduct() {}
public string ISBN
{
get {return isbnNum;}
set {isbnNum=value;}
}
}
public class Inventory
{
private Product[] stuff;
public Inventory() {}
//need to have an attribute entry for each data type
[XmlArrayItem("Prod",typeof(Product)),
XmlArrayItem("Book",typeof(BookProduct))]
public Product[] InventoryItems
{
get {return stuff;}
set {stuff=value;}
}
public override string ToString()
{
StringBuilder outText = new StringBuilder();
foreach (Product prod in stuff)
{
outText.Append(prod.ProductName);
outText.Append("\r\n");
}
return outText.ToString();
}
}
code snippet frmSerial.cs
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