Understanding the Event-Driven Model & Editions of Visual Basic 6

Understanding the Event-Driven Model

            In traditional or "procedural" applications, the application itself controls which portions of code execute and in what sequence. Execution starts with the first line of code and follows a predefined path through the application. calling procedures as needed.

In an event-driven application, the code doesn't follow a predetermined path — it executes different code sections in response to events. Events can be 'triggered by the user's actions. by messages from the system or other applications, or even from the application itself. The sequence of these events determines the sequence in which the code executes, thus the path through the application's code differs each time the program runs.

your code can also trigger events during execution. For example, programmatically changing the text in a text box cause the text box's Change event to occur. This would cause the code (if any) contained in the Change event to execute. If you assumed that this event would only be triggered by user interaction, you might see unexpected results. It is for this reason that it is important to understand the event-driven model and keep it in mind when designing your application.

Editions of Visual Basic 6

Learning Edition

This edition provides all intrinsic contrcis along with grid, tab and data bound controls. It is accompanied by Microsoft Developer Network(MSDN) plus a Learn VB Now CD.

Professional Edition

Apart from the learning edition controls, you have ActiveX Controls and Internet Controls, Active Data Objects, Integrated Visual Database Tools and Data Environment, Dynamic HTML Page Designer. The documentation includes Visual Studio Professional Features Book plus Microsoft Developer Network CDs containing full online documentation.

Enterprise Edition

The Enterprise Edition allows professionals to create robust distributed applications in a team setting. It includes all the features of Professional Edition, plus SQL Server, Microsoft Transaction Server, Internet Information Server, Visual SourceSafe, and more. Documentation includes Visual Studio Enterprise Features book plus MSDN CDs.