XmlRootAttribute

   
 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Xml;
using System.Xml.Serialization;

public class MainClass {      //new products object
    public static void Main() {
        XmlAttributes attrs = new XmlAttributes();
        attrs.XmlElements.Add(new XmlElementAttribute("Book", typeof(BookProduct)));
        attrs.XmlElements.Add(new XmlElementAttribute("Product", typeof(Product)));
        XmlAttributeOverrides attrOver = new XmlAttributeOverrides();
        attrOver.Add(typeof(Inventory), "InventoryItems", attrs);
        Product newProd = new Product();
        BookProduct newBook = new BookProduct();

        newProd.ProductID = 100;
        newProd.ProductName = "Product";
        newProd.SupplierID = 10;

        newBook.ProductID = 101;
        newBook.ProductName = "New Product";
        newBook.SupplierID = 10;
        newBook.ISBN = "123456789";

        Product[] addProd = { newProd, newBook };

        Inventory inv = new Inventory();
        inv.InventoryItems = addProd;
        TextWriter tr = new StreamWriter("inventory.xml");
        XmlSerializer sr = new XmlSerializer(typeof(Inventory), attrOver);

        sr.Serialize(tr, inv);
        tr.Close();
    }

}

[System.Xml.Serialization.XmlRootAttribute()]
public class Product {
    private int prodId;
    private string prodName;
    private int suppId;
    private int catId;
    private string qtyPerUnit;
    private Decimal unitPrice;
    private short unitsInStock;
    private short unitsOnOrder;
    private short reorderLvl;
    private bool discont;
    private int disc;

    [XmlAttributeAttribute(AttributeName = "Discount")]
    public int Discount {
        get { return disc; }
        set { disc = value; }
    }

    [XmlElementAttribute()]
    public int ProductID {
        get { return prodId; }
        set { prodId = value; }
    }
    [XmlElementAttribute()]
    public string ProductName {
        get { return prodName; }
        set { prodName = value; }
    }
    [XmlElementAttribute()]
    public int SupplierID {
        get { return suppId; }
        set { suppId = value; }
    }

    [XmlElementAttribute()]
    public int CategoryID {
        get { return catId; }
        set { catId = value; }
    }

    [XmlElementAttribute()]
    public string QuantityPerUnit {
        get { return qtyPerUnit; }
        set { qtyPerUnit = value; }
    }

    [XmlElementAttribute()]
    public Decimal UnitPrice {
        get { return unitPrice; }
        set { unitPrice = value; }
    }

    [XmlElementAttribute()]
    public short UnitsInStock {
        get { return unitsInStock; }
        set { unitsInStock = value; }
    }

    [XmlElementAttribute()]
    public short UnitsOnOrder {
        get { return unitsOnOrder; }
        set { unitsOnOrder = value; }
    }

    [XmlElementAttribute()]
    public short ReorderLevel {
        get { return reorderLvl; }
        set { reorderLvl = value; }
    }

    [XmlElementAttribute()]
    public bool Discontinued {
        get { return discont; }
        set { discont = value; }
    }
}
public class Inventory {

    private Product[] stuff;
    public Inventory() { }
    [XmlArrayItem("Prod", typeof(Product)),
    XmlArrayItem("Book", typeof(BookProduct))]

    public Product[] InventoryItems {
        get { return stuff; }
        set { stuff = value; }
    }
}

public class BookProduct : Product {
    private string isbnNum;

    public BookProduct() { }

    public string ISBN {
        get { return isbnNum; }
        set { isbnNum = value; }
    }
}