Server Controls and writing ASP.Net

Server Controls and Validation

We have already used server controls in many of the examples of building ASP.NET pages in previous chapters. In this chapter and the two that follow, we are going to be looking in more depth at exactly what server controls are and how we can use them. In fact, we will be examining all the different types of server controls that are supplied with the standard .NET installation.

Server controls are at the heart of the new ASP.NET techniques for building interactive web forms and web pages. They allow us to adopt a programming model based on server-side event handling that is much more like the structured event-driven approach we are used to when building traditional executable programs.

Of course, as the .NET framework is completely extensible, we can build our own server controls as well, or just inherit from existing ones and extend their behavior. We will look at how we can go about building our own server controls later in this book. In the meantime, we will stick to those that come as part of the standard .NET package.

The topics we will cover in this chapter are:

* What are server controls.
* How to build interactive forms and pages using them.
* The server controls supplied with .NET.
* A detailed look at the HTML and Input Validation controls

writing ASP.Net

You have already taken a high-level look at the .NET Framework, and seen a few quick examples of ASP.NET pages, so now let's dive in and look in more details at how to create ASP.NET pages. Whether they are called ASP.NET pages or Web forms, these files form the core of all ASP.NET applications.

* The old way of creating ASP pages versus the new way with ASP.NET.
* The steps a page goes through as it is processed.
* How to use the various features of the Page object.
* Breaking up a page into reusable objects called user controls.