Visual Basic 2005 in a Nutshell, Third Edition

The Structure of a Visual Basic Program | 93

Program

Structure

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New in 2005. The new Global keyword provides a way to resolve conflicts in

namespace usage. For instance, if your application included a namespace named

MyCompany.System, and you used the

Imports MyCompany statement in your code

file, would a reference to “System” mean the .NET-supplied System namespace or

the MyCompany.System namespace? The

Global keyword solves the problem. To

access the .NET-supplied System namespace, reference

Global.System, which

removes any ambiguity.

Types

Most of your application is defined through types: the classes, structures, enumer-

ations, interfaces, and so on, of your application. Many types can be nested.

Public Class ClassDepth1

Public Class ClassDepth2

' ----- Add code here.

End Class

' ----- And here, too.

End Class

Types contain members, mainly the methods, properties, events, and fields of

your classes and structures. Members cannot be nested, although members with

the same name may appear within different nested types. For instance, if Class

A

contains Class B, both A and B may include a procedure named ProcessData

without conflict.

The Structure of a Visual Basic Program

Broadly speaking, programs can be either procedure-driven or event-driven.Ina

procedure-driven program, program flow is