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Essential .NET, Volume I
After chapter one's history of the evolution from COM to the CLR, the book takes a bottom-up approach to the CLR, starting with a deep and detailed six chapter look into the core elements of the platform. Chapter two begins with assemblies, the programmatic units in the CLR, and the implications of their construction. We learn how they are versioned, loaded and built, and why therefore they may be written in as many .NET languages as required. There's real depth to the material here -- you really do touch the bottom of the abyss, so to speak -- but it's countered with occasional levity that keeps this a readable book instead of a dense reference manual. The same is true of all the text. To wit, there's even some irony; "To allow old dogs to avoid learning new tricks, there is finalization," he declares in the next section on the Common Type System.
It's here that we discover how different types and interfaces are distinguished from themselves and from one another, and how their variations and relationships are kept separate by the CLR. It's refreshing to note that the proverbial big picture is never very far away from the commentary. After taking time to explore the avenues for types and interfaces, Box notes that types themselves aren't very interesting until you start working with instances of those types, and we're off again working through another thirty pages on how object instances preserve a sense of identity, how they are cast into other types and how they incorporate themselves into the concepts of reflection and metadata. Only then do we look at the actual lifecycle of an object, its creation, modification and disposal. The attention to detail is great, and there's little ambiguity in the text, but with that comes a slowness to this section that may leave readers frustrated.
One recurring theme of the book is the idea that while there is a very proper way and set of rules for doing things, there will always be circumstances in application development which call for exceptions to be made to those rules and made possible by .NET. This is true at a small scale and, as chapters six and seven prove, at a large one too, covering as they do how the CLR calls and runs methods first on a single machine and then over a wire. How does the runtime treat methods called explicitly, implicitly through a delegate, asynchronously, or as a combination of the three? How do remote calls and types bridge whatever gaps they must cross and activate the remote objects and methods they're targeting? The answers are here.
Essential .NET reflects Box's pride in .NET and also his slight dissatisfaction with it. You can sense that while he knows .NET version 1 is an improvement over COM, it's not as good as it could be and things are still be done in v2 and beyond. Chapter eight's look at AppDomains and in particular its discourse on threading within and through AppDomains is a good example of this. Meanwhile, we finally come full circle in our investigation of the CLR, seeing how the assemblies we built in Chapter 2 are resolved and executed within AppDomains. Exceptions to rules being included, we also see how objects references are marshaled across AppDomains for inter-application communication if this is required.
The last two chapters look at wider topics around the CLR in as much detail as they can for topics which have entire books dedicated to just them. Chapter nine covers code-access security and chapter ten topics which are not of the CLR but which be can be addressed from within a .NET application: explicit memory management, using p/invoke to import COM methods from DLLs and so on. Both are concisely written and to the point, but unsurprisingly leave you feeling like there's more to these topics than is covered here. Chapter nine is a great and clear introduction to code-level security, for example, but you'll get a lot more out of Michael Howard's book, Writing Secure Code if you want to know more.
Essential .NET isn't an easy read but everyone should try to read it at least once. Focusing on the CLR itself and how it deals with the components of an application means that it truly is aimed at the community of .NET developers as a whole (including those building and using alternate implementations of the CLR). The provided code examples are expressed in C#, but this is incidental, really, and won't stop VB.NET, J# or any other developers getting a great deal out of this book.
This is a dense, complex volume that requires a fair amount of effort to understand and use, and to some extent this may put people off. On the other hand, it is so packed with great nuggets of information that they may be inspired to keep reading. Of course, there is the question of whether this book will actually improve your .NET development skills, but in riposte, you can honestly say that no volume details the CLR and its potential so well, and that this alone is worth the book's cover price.
You can purchase Essential .NET, Volume One from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
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but your statement is not quite correct, unless I am not fully informed which is definately a possibility.... I have been finding more and more differences between programming for
The big difference between the ASP.NET paradigm and that of, say, Java Servlet Pages, or XSP, etc. lies in the event-based nature of ASP.NET pages.
.aspx page). The .aspx page is parsed on each request, but the code-behing is pre-compiled.
Each ASP.NET page is an instance of the "Page" class, or one of its sub-classes. The "Page Lifecycle" defines the various phases that apply each time a page is accessed. The "Page" is simply the top-level node in the "control tree", and each control in the tree does the following for all its children (recursively):
1. initialization
2. handle postback data
3. state management
4. handle events
5. pre-render stuff
6. render to HTML (or whatever)
7. clean up
Most of your code will pertain to numbers 4 and 5 above, if done correctly.
It's not immediately intuitive, coming from a Web App developer's perspective, but does provide a good general structure and mechanism.
In addition, each Page is split into its actual class (the so-called "code-behind page"), and its representation as markup (the
ASP.NET provides a robust programming model for web applications, but it also provides a lot of built-in mechanisms for doing common stuff. Authentication, Authorization, Caching, DataBinding, XML, conditional rendering, templating, data access through ADO.NET, internationalization, Debugging and Tracing utilities, and more.
That said, I find the event-based programming model quite difficult to master. If used improperly, you can end up running the same code many times; for instance of you populate a given control (say a dropdown) from a database, and do so in response to many different events. Better to flag things and then fetch just once from the DB prior to rendering.
Thoughts?
PS: At the moment, you can't mix multiple languages (C#, VB.NET) within a single Web App.
You can pick up a description of the VM and write one from scratch if you are so inclined, and the JCP controls how the platform develops - in all ways that matter, Java is a standard.
Have a look at www.jcp.org if you want to see a more developer accessible standards process.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
This is one of the best .NET books, the first of a series of pretty good books, by those involved deeply with the framework.
.NET framework, and is of special interest if you are interested in the advanced features of the Common Language Runtime like method interception, transparent proxies, application domains and metadata.
This book covers the technicalities in the
Compiler writers, framework developers and those who need to get the most out of the framework will be interested in this title.
I can not recommend this book enough. Don has done a fantastic job. It helped the Mono developers understand the low-level technical features of the framework.
Miguel.
Mono is an implementation of the ECMA 334 and 335 standards which are available for anyone to implement (no patent strings attached, check the Mono FAQ for details).
On top of that Mono implements plenty of class libraries: both the non-standarized class libraries from Microsoft, as well as our own universe of class libraries that take advantage of Unix-specific features.
Here is a link: Mono Map (abridged).
Miguel.
Various publishers are working on books about Mono that will cover exactly what you want.
.NET book applies directly to Mono. In fact, before Don joined Microsoft, he was kind enough to let us preview his book, and that helped us understand various internals of the .NET framework.
But everything you learn in Don's Essential
Miguel.