Chapter 10 : Programming ASP.NET Pages

Overview

This is the first of two chapters addressing Microsoft ASP.NET Web applications. ASP.NET is the name for the .NET Framework subset of Web development capabilities. This chapter has two primary objectives. First, the chapter aims to introduce Web development concepts, particularly those implemented through ASP.NET. Second, the chapter aims to give you an operational feel for how to create ASP.NET solutions with Microsoft Visual Basic .NET. The chapter reviews the design and construction of three ASP.NET Web sample applications to illustrate how you build Web solutions with Visual Basic .NET. Creating database solutions with ASP.NET is specifically excluded from this chapter to keep the focus on ASP.NET and clearly present Web applications from a tutorial perspective. Chapter 11 focuses on creating ASP.NET solutions for Microsoft Access databases.

This chapter contains three sections. The first section describes ASP.NET platform requirements and contrasts ASP.NET Web applications with Windows applications and Active Server Pages (ASP) applications. The discussion of platform requirements conveys what you need to build ASP.NET solutions and contrasts these requirements with those for running ASP.NET solutions. For example, this section explains that you can run an ASP.NET solution from a workstation that does not have the .NET Framework installed on it. You will also learn about the important topic of Web pages making round-trips between a browser and a server and its implication for Web page processing.

The chapter s second section drills down further into ASP.NET by presenting important ASP.NET programming concepts, such as the Web Forms Page class and controls for this class. Although you can use Visual Basic .NET to build Web applications and Microsoft Windows applications on forms, the forms and the controls on those forms differ for each type of application. This section highlights special issues pertaining to forms and controls for Web applications.

The third section in the chapter demonstrates how to create ASP.NET solutions by presenting the steps for building and evaluating three sample ASP.NET Web applications. The first sample introduces you to the basics of adding a Web form to a solution and using that solution. The second sample builds on the initial sample in a couple of ways. First, it shows how to move controls around a Web page programmatically. The process is different than that for moving controls around a Windows form. Second, the application demonstrates how to refresh a Web solution programmatically. The solution demonstrates a workaround to a problem with the Refresh tool on browsers for ASP.NET solutions. The third sample demonstrates how to use Session variables to track the values of variables across multiple forms in a Web application. The sample illustrates a simple approach to authenticating users with a Web form.