VB.NET Language in a Nutshell, Second Edition

Chapter 6. The .NET Framework Class Library

VB.NET is about classes, classes, and more classes. Even something as simple as a string is implemented in a class (the String class of the System namespace). As we mentioned in Chapter 5, the .NET Framework defines an extensive network of classes and namespaces called the Framework Class Library (FCL). This consists of a set of namespaces that provide basic system services (like the System namespace, whose classes define .NET data types, provide exception handling, and handle garbage collection, among other things). It also includes additional namespaces, such as System.Data, System.Windows. Forms, and System.Web.UI, which provide application services. In total, there are over 90 namespaces containing several thousand classes, interfaces, structures, enumerations, and other items (such as delegates) in the .NET Framework Class Library.

The System namespace is at the top of the namespace hierarchy, and the Object class is at the top of the object hierarchy. All types in the .NET Framework Class Library derive from the Object class.

The .NET Framework Class Library is sufficiently extensive to require an entire book for its description. In this chapter, we provide just a brief introduction and some examples. This should prepare you to dive into the Microsoft Class Library documentation. Note also that the reference portion of this book, Chapter 10, documents selected language elements from the Framework Class Library that seem particularly ...