Using Object-Orientation in ASP.NET : Encapsulation, Part 2

By Ian Stallings

In Part 1 we examined the basics of encapsulation and a simple Foo class. In this page we'll examine how to utlize this class (thereby showing the benefits of encapsulation)! For our example, we'll call this class from our ASP.NET file using the following code:

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<%@ Import Namespace="KungFoo" %> <html> <style> div { font: 8pt verdana; background-color:cccccc; border-color:black; border-width:1; border-style:solid; padding:10,10,10,10; } </style> <script language="C#" runat="server"> public void Page_Load(Object sender, EventArgs E) { Foo foo = new Foo(); Message.InnerHtml += foo.getPhoneNumber() + "<p>"; foo.setPhoneNumber("702-555-1212"); Message.InnerHtml += foo.getPhoneNumber() + "<p>"; } </script> <body style="font: 10pt verdana"> <b><h3>Simple Biz Obj</h3></b> <br><br> Object Output:<br> <br> <div id="Message" runat="server"/> </body> </html>

This should produce the following output:

Notice that when we did not alter the state of the object directly. Instead we called a behavior of the object named setPhoneNumber. We aren't worried about how this is accomplished. That's the great part. It hides the implementation details. For all we know there could be a "Hamster in a Wheel" class that makes this happen.

And that wraps up encapsulation. In our next article we will discuss inheritance and how it can be used to develop ASP.NET to create reusable and extensible code.

Happy Programming!

By Ian Stallings

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