Programming ASP .NET

Binding to a Class

In the previous example, you bound an ArrayList of strings to the list box. Often, you will want to bind objects more complex than strings. For example, you might imagine a Book class that has properties such as title, ISBN, and price, as shown in Example 9-3 (C#) and Example 9-4 (VB.NET).

Example 9-3. The Book class in C#

public class Book
{
   public Book(float price, string title, string ISBN)
   {
      this.price = price;
      this.title = title;
      this.isbn = ISBN;
   }

   public float Price { get {return price;} }
   public string Title { get {return title;} }
   public string ISBN { get {return isbn;} }

   private float price;
   private string title;
   private string isbn;

}

Example 9-4. The Book class in VB.NET

Public Class Book

   Private _Price As Double
   Private _Title As String
   Private _ISBN As String

   Public Sub New( _
       ByVal thePrice As Double, _
       ByVal theTitle As String, _
       ByVal theISBN as string)
      _Price = thePrice
      _Title = theTitle
      _ISBN = theISBN
   End Sub

   Public ReadOnly Property Price(  ) As Double
      Get
         Return _Price
      End Get
   End Property

   Public ReadOnly Property Title(  ) As String
      Get
         Return _Title
      End Get
   End Property

   Public ReadOnly Property ISBN(  ) As String
      Get
         Return _ISBN
      End Get
   End Property

End Class

You add the new book objects to the ArrayList, just as you assigned the strings, shown here in C#. (The VB.NET code is the same except without the semicolons.)

bookList.Add(new Book(49.95f, "Programming ASP.NET","100000000")); bookList.Add(new Book(49.95f,"Programming C#","0596001177")); ...