How C Relates to the .NET Framework

How C# Relates to the .NET Framework

Although C# is a computer language that can be studied on its own, it has a special relationship to its runtime environment, the .NET Framework. The reason for this is twofold. First, C# was initially designed by Microsoft to create code for the .NET Framework. Second, the libraries used by C# are the ones defined by the .NET Framework. Thus, even though it is possible to separate C# the language from the .NET environment, the two are closely linked. Because of this, it is important to have a general understanding of the .NET Framework and why it is important to C#.

What Is the .NET Framework?

The .NET Framework defines an environment that supports the development and execution of highly distributed, component-based applications. It enables differing computer languages to work together and provides for security, program portability, and a common programming model for the Windows platform. As it relates to C#, the .NET Framework defines two very important entities. The first is the Common Language Runtime (CLR). This is the system that manages the execution of your program. Along with other benefits, the Common Language Runtime is the part of the .NET Framework that enables programs to be portable, supports mixed-language programming, and provides for security.

The second entity is the .NET Framework class library. This library gives your program access to the runtime environment. For example, if you want to perform I/O, such as displaying something on the screen, you will use the .NET library to do it. If you are new to programming, then the term class may be new. Although it is explained in detail later in this book, for now a brief definition will suffice: a class is an object-oriented construct that helps organize programs. As long as your program restricts itself to the features defined by the .NET Framework class library, your programs can run anywhere that the .NET runtime system is supported. Since C# automatically uses the .NET Framework class library, C# programs are automatically portable to all .NET environments.