Visual Basic Design Patterns: VB 6.0 and V.NET [Paperback]

The author starts off by explaining what design patterns are; this is one of the best introductions to the topic that I have read. The following 7 chapters introduce UML, OO Programming and VB.NET. In my opinion, these topics cannot be explained in fewer than 100 pages of any book and hence should have been prerequisites on our part (the readers). The result is that the coverage is neither broad nor deep, but nevertheless serves at getting us all on level ground.

The remainder 360 pages focus on describing all the patterns found in the Gamma et al book. It is all very good stuff doing justice to the title, as every pattern description (bar one) is accompanied by examples in both VB6 and VB.NET. Books are coming out continuously that describe various areas of the .NET framework, of the VB language, migration issues etc. It is pleasant to see a book that discusses the deeper aspect of programming good OO software using infamous design patterns.

Depending on your programming domain, you will be delighted or disappointed that almost all examples are GUI based (no component stuff here). Also, this is not a book from one VB programmer to another. On contrary, it is evident that the author's first language is not VB and references to Java/Smalltalk can be found in the text. Irrelevant as that may be, I would have preferred to have seen events (VB6) and delegates (VB.NET) to have been leveraged in the patterns.

To finish on a positive note, this book (and the CD with all examples' code that accompanies it) serves as a good reference while writing software in VB6 and VS.NET

The problem with this approach, and this book in particular, is that the author tend to ignore the language specific features to make his/her life easier. And this is precisely the problem with this book: the author could as well have published even more language versions because the discussion is so "language-neutral" and all the examples given are so un-VB... I can easily imagine the same examples implemented with Tcl/Tk or Delphi or any other modern programming language, for that matter.

Let's face it. We choose a lanaguage for a certain task because the language has certain desirable feature(s) to make our life easier: the right tool for the right job. As such the approach taken in this book is flawed: "OK, we've got this pattern in GoF, so let's see how we can implement this in VB and VB.NET using the smallest feature set possible" (actually I suspect it's the feature set that intersects with Java most). So we end up with patterns implemented in the "obvious way", which for almost all languages is not the preferrable way because there are probably some specific language features to exploit. This book doesn't, in particular, take advantage of the language's greatest strength: COM integration. Why would a VB programmer choose not to use COM when it is possible, and in many cases more suitable, to implement the design patterns dicussed?

I seriously recommend you to first glance through this book (in person) before you buy it. Better yet, also check out Stamatakis' VBDP book. (Yes, this one uses COM.)

It's not that his code is faulty, it all makes sense when you open up the CDRom and go through things slowly, but the snippets in the book are too sparse to really follow without having your computer on and the VB projects open before you. This "sparseness" was likely done to keep the book's length down some, and if you don't mind looking at your monitor as you read the chapters then I suppose you'll do ok.

My inclination however, is to read the chapters first, *then* look at the code, and I just couldn't do that here and make sense of things. Also, I didn't particularly enjoy some of the sample programs (I thought the "swim meet" samples were somewhat convoluted, for instance), but that could just be my problem.

Now that the critiques are out of the way, I'll give the author credit for doing a good job in explaining why you would use design pattern XYZ and under which circumstances, and for listing pattern examples in both VB 6 and VB .Net. It's certainly not a bad book, just a little tough to follow without VB sitting open next to you.