.NET and COM Interoperability Handbook, The

Types

The .NET Framework is built around types. A type in .NET is a class, structure, interface, enumeration, or delegate. Every piece of code that you write in .NET, even the main program for your application, must be a member of some type.

The following code shows the simplest “hello world” application that you can write.

class TestClass
{
  static void Main(string[] args)
  {
    System.Console.WriteLine("Hello World");
  }
}

Notice that the Main method in this case is a static member of a class called TestClass. Not only will all of the code that you write be contained within some type, but all of the code that you use, both the classes in the .NET Framework base class library and any third-party class libraries, are all implemented as types. There ...