Wednesday, March 18, 2020
The eNotes Blog Top Ten Summer ReadingSuggestions
Top Ten Summer ReadingSuggestions Since I was a very small child, the absolute best thing about summer was the extra time to read. My mother, fed up with me being in the house, would throw me outside to get some sunshine. So I took my book outside, sat on the porch, and waited to be let in. Like a cat. Summer is still the best time to get some reading done and the time that a lot of my professorial/literary snot friends (stop protesting you know its true) unbutton that top button and go for some non-standard fare. But the choices can be overwhelming: Here are suggestions for some good pleasure reading for fun and even knowledge to help you get the most out of those precious extra hours: 1.  Mr. g by Alan Lightman How about a little blasphemy to go with that daiquiri? One friend heartily suggests this novel. Publishers Weekly calls Mr. G a touching, imaginative rendition of God’s creation of the universe†¦the immortal characters are changed by their brush with the enterprising, however doomed, mortals, bringing this elucidating treatment of quantum physics to an affecting, hopeful conclusion.†2.  The Prague Cemetery by Umberto Eco Several friends asked for this novel by the Italian mystery/detective master (who penned The Name of the Rose and Foucaults Pendulum) to be included. I find this book fascinating, perhaps the best Eco has written in years. Eco takes on conspiracy theories in the feverish political activism of nineteenth-century Europefreemasonry, the Italian Risorgimento, the Paris Commune, and above all the forgery of the slanderous The Protocols of the Elders of Zion. What if there were a single mastermind behind all these conspiracies? Its already a bestseller in Italy, and I cant get enough of it! ~ Huffington Post 3.  Lets Pretend This Never Happened by Jenny Lawson Those of us who have been LONGTIME fans of The Bloggess are beside ourselves with glee at the arrival of Lawsons first traditional book. Just take a look at these chapter titles, will ya? â€Å"Stanley the Magical, Talking Squirrel†; â€Å"A Series of Angry Post-It Notes to My Husband†; â€Å"My Vagina Is Fine. Thanks for Asking†; â€Å"And Then I Snuck a Dead Cuban Alligator on an Airplane.†She is hysterical and you should buy this book. Now. 4.  Sacre Bleu: A Comedy DArt by Christopher Moore This selection was heralded by several people. Heres the scoop: In July 1890, Vincent van Gogh went into a cornfield and shot himself. Or did he? Why would an artist at the height of his creative powers attempt to take his own life . . . and then walk a mile to a doctors house for help? Who was the crooked little color man Vincent had claimed was stalking him across France? And why had the painter recently become deathly afraid of a certain shade of blue? These are just a few of the questions confronting Vincents friends- baker-turned-painter Lucien Lessard and bon vivant Henri Toulouse-Lautrec- who vow to discover the truth about van Goghs untimely death. Their quest will lead them on a surreal odyssey and brothel-crawl deep into the art world of late nineteenth-century Paris. 5.  Kitty Cornered by Bob Tarte Tarte has a remarkable ability to depict animal behavior and see the humor (and toils) of  pets without anthropomorphizing his beloved menagerie. Fans of his previous work (Enslaved by Ducks, Fowl Weather) will once again delight in the various antics of all his animals, but will appreciate the focus on his six quirky felines. I dare you not to fall in love with Frannie and all the others. 6.  11/22/63 by Stephen King King, of course, has been a popular favorite for over thirty years but he has not always enjoyed critical acclaim; this novel, however, has garnered both. Most people will instantly recognize 11/22/63 as the infamous date when President John F. Kennedy was assassinated. King imagines what would happen if a time traveler was able to go back to that fateful day and change the course of history. 7.  Little Bee by Chris Cleave Also being tucked into beach bags this summer is Chris Cleaves Little Bee. If you enjoy riveting, character-based novels, this might be a good choice for you too.  Here is what the Washington Post had to say: Little Bee will blow you away. In restrained, diamond-hard prose, Cleave alternates between these two characters points of view as he pulls the threads of their dark but often funny story tight. What unfolds between them is both surprising and inevitable, thoroughly satisfying if also heart-rending. 8.  Sandman (Series) by Neil Gaiman Sometimes summer demands becoming totally obsessed with a series.  You couldnt ask for a better way to spend dozens of hours than to be immersed in Gaimans series of graphic novels. The Sandman novels are a rich blend of modern myth and dark fantasy in which contemporary fiction, historical drama and legend. The works are  widely considered one of the most original and artistically ambitious series of the modern age. 9.  Incognito: The Secret Lives of the Brain by David Eagleman Looking for a good non-fiction read that also serves as a dandy excuse that no one will bother you about playing volleyball or frisbee or anything remotely athletic? This is the book for you. You get to learn all sorts of cool stuff here, like why you keep dreaming that dream about the elephant in your mothers underpantsor is that just me?  Seriously, though, Eaglemans study is a fascinating look into what goes on inside the brain, both consciously and unconsciously. Listen to a great interview with Eagleman on NPRs Fresh Air here. 10.  Undead and Undermined by Mary Janice Davidson Vampire Queen Betsy Taylor thought she couldnt die. So whats she doing in the morgue? It could have something to do with a time- traveling trip she made, and a foe with a wicked agenda that could finally be the real death of Betsy-if shes not careful. Cmon. You know you want to.   Tuck it into your snooty copy of Tolstoy if you must (be prepared to explain the funny parts though) or flaunt it and ask the person next to you if they would also enjoy some box wine and some Cheetos. Cmoooooon. its summer.
Sunday, March 1, 2020
Dispose Objects in Visual Basic
Dispose Objects in Visual Basic In the article, Coding New Instances of Objects, I wrote about the various ways that New instances of objects can be created. The opposite problem, disposing an object, is something that you wont have to worry about in VB.NET very often. .NET includes a technology called Garbage Collector (GC) that usually takes care of everything behind the scenes silently and efficiently. But occasionally, usually when using file streams, sql objects or graphics (GDI) objects (that is, unmanaged resources), you may need to take control of disposing objects in your own code. First, Some Background Just as a constructor (the New keyword) creates a new object, a destructor is a method that is called when an object is destroyed. But theres a catch. The people who created .NET realized that it was a formula for bugs if two different pieces of code could actually destroy an object. So the .NET GC is actually in control and its usually the only code that can destroy the instance of the object. The GC destroys an object when it decides to and not before. Normally, after an object leaves scope, it is released by the common language runtime (CLR). The GC destroys objects when the CLR needs more free memory. So the bottom line is that you cant predict when GC will actually destroy the object. (Welllll ... Thats true nearly all of the time. You can call GC.Collect and force a garbage collection cycle, but authorities universally say its a bad idea and totally unnecessary.) For example, if your code has created a Customer object, it may seem that this code will destroy it again. Customer = Nothing But it doesnt. (Setting a an object to Nothing is commonly called, dereferencing the object.) Actually, it just means that the variable isnt associated with an object anymore. At some time later, the GC will notice that the object is available for destruction. By the way, for managed objects, none of this is really necessary. Although an object like a Button will offer a Dispose method, its not necessary to use it and few people do. Windows Forms components, for example, are added to a container object named components. When you close a form, its Dispose method is called automatically. Usually, you only have to worry about any of this when using unmanaged objects, and even then just to optomize your program. The recommended way to release any resources that might be held by an object is to call the Dispose method for the object (if one is available) and then dereference the object. Customer.Dispose() Customer Nothing Because GC will destroy an orphaned object, whether or not you set the object variable to Nothing, its not really necessary. Another recommended way to make sure that objects are destroyed when theyre not needed anymore is to put the code that uses an object into a Using block. A Using block guarantees the disposal of one or more such resources when your code is finished with them. In the GDI series, the Using block is put to use quite frequently to manage those pesky graphics objects. For example ... Using myBrush As LinearGradientBrush _ New LinearGradientBrush( _ Me.ClientRectangle, _ Color.Blue, Color.Red, _ LinearGradientMode.Horizontal) ... more code ... End Using myBrush is disposed of automagically when the end of the block is executed. The GC approach to managing memory is a big change from the way VB6 did it. COM objects (used by VB6) were destroyed when an internal counter of references reached zero. But it was too easy to make a mistake so the internal counter was off. (Because memory was tied up and not available to other objects when this happened, this was called a memory leak.) Instead, GC actually checks to see whether anything is referencing an object and destroys it when there are no more references. The GC approach has a good history in languages like Java and is one of the big improvements in .NET. On the next page, we look into the IDisposable interface... the interface to use when you need to Dispose unmanaged objects in your own code. If you code your own object that uses unmanaged resources, you should use the IDisposable interface for the object. Microsoft makes this easy by including a code snippet that creates the right pattern for you. Click Here to display the illustrationClick the Back button on your browser to return The code that is added looks like this (VB.NET 2008): Class ResourceClass    Implements IDisposable    To detect redundant calls    Private disposed As Boolean False    IDisposable    Protected Overridable Sub Dispose( _       ByVal disposing As Boolean)       If Not Me.disposed Then          If disposing Then          Free other state (managed objects).          End If          Free your own state (unmanaged objects).          Set large fields to null.       End If       Me.disposed True    End Sub #Region IDisposable Support    This code added by Visual Basic to    correctly implement the disposable pattern.    Public Sub Dispose() Implements IDisposable.Dispose       Do not change this code.       Put cleanup code in       Dispose(ByVal disposing As Boolean) above.       Dispose(True)       GC.SuppressFinalize(Me)    End Sub    Protected Overrides Sub Finalize()       Do not change this code.       Put cleanup code in       Dispose(ByVal disposing As Boolean) above.       Dispose(False)       MyBase.Finalize()    End Sub #End Region End Class Dispose is almost an enforced developer design pattern in .NET. Theres really only one correct way to do it and this is it. You might think this code does something magic. It doesnt. First note that the internal flag disposed simply short-circuits the whole thing so you can call Dispose(disposing) as often as you like. The code ... GC.SuppressFinalize(Me) ... makes your code more efficient by telling the GC that the object has already been disposed (an expensive operation in terms of execution cycles). Finalize is Protected because GC calls it automatically when an object is destroyed. You should never call Finalize. The Boolean disposing tells the code whether your code initiated the objects disposal (True) or whether the GC did it (as part of the Finalize sub. Note that the only code that uses the Boolean disposing is: If disposing Then    Free other state (managed objects). End If When you dispose of an object, all of its resources must be disposed of. When the CLR garbage collector disposes of an object only the unmanaged resources must be disposed of because the garbage collector automatically takes care of the managed resources. The idea behind this code snippet is that you add code to take care of managed and unmanaged objects in the indicated locations. When you derive a class from a base class that implements IDisposable, you dont have to override any of the base methods unless you use other resources that also need to be disposed. If that happens, the derived class should override the base classs Dispose(disposing) method to dispose of the derived classs resources. But remember to call the base classs Dispose(disposing) method. Protected Overrides Sub Dispose(ByVal disposing As Boolean)    If Not Me.disposed Then       If disposing Then       Add your code to free managed resources.       End If       Add your code to free unmanaged resources.    End If    MyBase.Dispose(disposing) End Sub The subject can be slightly overwhelming. The purpose of the explanation here is to demystify whats actually happening because most of the information you can find doesnt tell you!
Subscribe to:
Posts (Atom)