Visual Basic Design Patterns: VB 6.0 and VB.NET

Chapter 30. The Strategy Pattern

The Strategy pattern is much like the State pattern in outline but a little different in intent. The Strategy pattern consists of a number of related algorithms encapsulated in a driver class called the Context. Your client program can select one of these differing algorithms, or in some cases, the Context might select the best one for you. The intent is to make these algorithms interchangeable and provide a way to choose the most appropriate one. The difference between State and Strategy is that the user generally chooses which of several strategies to apply and that only one strategy at a time is likely to be instantiated and active within the Context class. By contrast, as we have seen, it is possible that all ...