.NET Windows Forms in a Nutshell

The .NET Type System

So what does a type look like in .NET? In many respects, types are very similar to C++ classes: just like a C++ class, a .NET type is a collection of members, which may be fields (i.e., they hold data of some type), methods (i.e., they contain code), or nested type definitions, and all members have some level of protection (e.g., public, private, protected). However there are a number of differences between the C++ and the .NET type systems. The following sections describe the main features of types in .NET.

Members of Types

Any type will need to define some members to be of any use. Members are either associated with data or behavior. In C++ this means fields and methods, respectively. In addition to these, which the CLR supports, the CLR adds some new member types. All these member types are described here.

Methods

Methods are where we define code. In most .NET languages, all code must be defined in a method of some type. (Because properties also can contain code, they would appear to be an exception, but they are actually implemented by .NET language compilers as method calls.) As with C++, the method must have a signature (consisting of its name and the types of parameters it takes), and that signature must be different from any other methods defined in the same class. Overloading is allowed, i.e., the names of two methods can be the same if their signatures are different. Methods must also have a return type (even if the method returns void or Nothing ...