Section 2.6. The Framework Class Library

2.6. The Framework Class Library

Although .NET itself is very powerful and very cool, it doesn't provide much in the way of specific functionality. The .NET Framework provides a generic system for application development, but it's really all plumbing. It's not that different from the old-style C++ or Pascal compilers. If you want to sort a list of strings in reverse order by length, draw a line on the screen, interact with a database, or send a data packet across the Internet, you still have to write all of that functionality yourself. Or do you?

Fortunately, you don't have to do it all by yourself. The .NET Framework includes a library of prewritten features that provide a lot of the functionality you really wanted, but that you didn't want to write yourself. This library uses a layered approach. At the bottom of the library is the Base Class Library (BCL), which defines the central and common features that every .NET language will use, such as:

• Implementation of all core data types

• Data structures, such as stacks, queues, and collections

• Diagnostic and tracking features

• Basic input and output with various sources, such as files and serial ports

On top of this foundation you find the FCL, which is pretty much everything else that Microsoft thought programmers (including programmers designing the .NET system) would find useful. Among the many library classes are:

• XML manipulation tools

• ADO.NET, a collection of generic and platform-specific database interaction components

• GDI+, the core drawing system for on-screen and printed output

• Windows Forms, a package for creating desktop applications

• ASP.NET, a web-based programming system