Microsoft® Visual Basic® .NET Programmer's Cookbook

Use the Factory Pattern

Problem

You want the ability to create classes generically, without knowing their specific types.

Solution

Create a dedicated factory class that can construct the type of class you need.

Discussion

The factory pattern is one of the best-known creational patterns. It provides an abstracted mechanism for creating classes.

In the factory pattern, as shown in Figure 4-4, every class has its own corresponding factory class. In order for the factory pattern to work, all of these classes must derive from two abstract base classes.

Figure 4-4. The abstract factory pattern

For example, imagine you want to create a generic component that queries ...