Professional Design Patterns in VB .NET: Building Adaptable Applications [Englisch] [Taschenbuch]

Rather than attempting to compete with 'Design Patterns : elements of Reusable Object-Oriented Software', from Addison-Wesley, they extend it so that VB developers can learn how to understand design Patterns and apply them inside our applications.

The book covers the following common patterns :
Singleton, Abstract Factory, Factory, Adapter, Facade, Bridge, Composite, Decorator, Proxy, Observer, State, Strategy,Template.

The book begins with a chapter that explains the basic premise behind the most common creational, behavioral and structural patterns. This chapter is excellent and provided me with the most insight into how I could change the way I develop applications using patterns.

The next chapters deal with how to implement these patterns in the data tier, middle tier and presentation tier. The examples are illustrative, if nothing else. BEWARE THEIR CODING TECHNIQUES! The authors actually implemented the disposal of unmanaged resources like database connections inside of a Finalize() method!!! With the .NET Framework's implementation of automatic garbage collection, this is the absolute last thing you'd ever want to do with an unmanaged resource. They should have used the IDisposable interface.

I'll give them three stars for their treatment of the topic, but these guys are lousy .NET coders.

The books offers one of the most fascinating concepts in developing the presentation tier, called MVC, a.k.a. Model, View, Controller. MVC decouples the user interface from the form/control events on a form and placing this logic in a controller class or classes. The controllers have full control of the model aspect of the framework where the controller puts data in the view or the user interface from the model.

MVC uses patterns within its framework. For example the controller is made of algorithms and therefore is a strategy pattern. The relationship between the view and model is an observer pattern, while the view is a composite and the relationship from the view to the controller is a factory pattern. Using the factory pattern the controller is created, uses the data in the model and the view is updated via the observer. The book however goes into to detail how to forgo the observer pattern by using data binding with ADO.NET and a data grid. The observer pattern in MVC is not explained, other than in the beginning of the book as the pattern itself as opposed relating to a framework.

You are not limited to just these patterns within MVC. I have used the visitor pattern, the mediator pattern and the command patterns within my controller classes to achieve different methods to communicate and alter the data within the model. It is my opinion that as long as the View, the Model and the Controllers are decoupled from each other then you have achieved MVC.

With excellent code and UML examples, I suggest owning this book as I find myself studying it time and time again attempting to master MVC and implementing best practice with design patterns. Another good book I highly recommend is C# Design Patterns.