ASP.NET 2.0 All-In-One Desk Reference For Dummies®

Chapter 4. Understanding Postback, Events, and Code-Behind

In This Chapter

✓	Posting pages to the server
✓	Working with events in Visual Basic
✓	Working with events in C#
✓	Getting behind the scenes of code-behind

Three of the most important concepts in ASP.NET programming are the ideas of (1) posting pages to the server, (2) handling events, and (3) code-behind. Postback refers to what happens when the user clicks a button or performs some other action that sends the page displayed in the browser window to the server so whatever data the user entered on the page can be processed. Events are the processes that ASP.NET uses to deal with user interaction when a page has been posted. And code-behind is how ASP.NET lets you separate the code that’s executed when events occur from the markup code that defines how pages appear.

This chapter introduces you to these three all-important ASP.NET concepts.

All code listings used in this book are available for download at www.dummies.com/go/aspnetaiofd.

Understanding Postback

You’re probably familiar with Web pages that include a Submit button. For example, consider a typical search-engine Web page that has a text box and a Submit button. When you click the Submit button, the text you entered into the text box is sent to the search-engine’s server, which looks up the results of your search and sends the results back to the browser. The process of sending ...