In this article, I discuss how one can be able to understand Bridge Pattern using vb.NET programming and what the bridge patter allows one to do in vb.net programming.
Think of a component set in which the components are interchangeable. One can upgrade the speakers for deeper bass. If the CD-player does go bad, one can similarly buy a new CD-player and then plug it into the Amplifier and he is good to go again.
The CD-Player – through the Amplifier does produce a signal that is not useful to human beings. One still has a problem hearing the music. He can, however, feed that signal into the speakers directly. The signal will then make an electro-magnet that is connected to the speaker cone to jump in tandem with the music. This jumping of the speaker cone does cause it to collide with air molecules that surround it, thereby producing vibrations in the air that the human ear can really hear. After this one will have an actual implementation.
In the bridge pattern in vb.net programming there exists an abstraction interface that dictates that any class implementing it must be able to create an abstraction of the work that is to be done. In this article I call it an expression of the work. Also in the pattern there are the refined abstractions. I imagine the vb.net programming people avoided the term concrete-abstraction because it is a bit of an oxymoron. These refined-abstractions are the real classes that produce the expressions of work. One could also think of them as the real signal-producers. In the earlier example of the music system, these are Tuners, CD-players, Turntables, etc.
The bridge pattern in vb.net programming also has an abstract implementer. This is can be compared to a music system for speakers. This dictates that the device must accept a musical signal and then produce an audible vibration based on that particular signal. Finally, the pattern does include the concrete implementers. These are like the real speakers or headphones. They do accept the signal that is produced by the CD-player and they vibrate their cones rapidly in order to produce something one can hear. In fact, twenty years from now when energy is at a premium and every single watt has to be saved one can expect that speakers will evolve to become very tiny electrodes which one can clip on to his ears. The point I am trying to put across here is that there is flexibility in the way the device functions. As long as one hears the music then that is all that matters as the music is implemented.
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