Introduction

Chapter 1 provided an overview of Visual Basic .NET applications; let s now look more closely at the various components of the .NET Framework. The .NET Framework includes a number of base classes, which you will use to begin. The Framework includes abstract base classes to inherit from as well as implementations of these classes to use. You can even derive your own classes for custom modifications. All the classes are derived from the system object. As you can imagine, this gives you great power and flexibility. Some of this power was previously available in Visual C++, but now you can have this same power within Visual Basic. All applications will share a common runtime environment called the Common Language Runtime (CLR). The .NET Framework now includes a common type system. This system allows all the languages to share data using the same types. These features facilitate cross-language interoperability.

To use .NET, you are required to learn some new concepts, which we discuss throughout this chapter. A Visual Basic .NET application is wrapped up in an assembly. An assembly includes all the information you need about your application. It includes information that you would find currently in a type library as well as information you need to use the application or component. This makes your application or component completely self-describing. When you compile your application, it is compiled to an intermediate language called the Microsoft Intermediate Language (MSIL) . When a program is executed, it is...