[dba-Tech] C++ to vb.net conversion

>In my programming career, I've probably written 300,000 lines of code, but
none of it in classes.  And you're probably rolling your eyes about now!

Not at all.  I learned OO programming using TurboPascal in the late 80s.
When I moved to Access AFAIK it didn't have classes back then so I "lost
it", went back to procedural methods simply because that was all the tool
provided.  I only started using classes in Access about 5 years ago.  I must
say that I now use them a LOT.  

Sooo... Here ya go, about as simple as it gets, but it demonstrates
admirably the benefits of a class.  Insert a class and cut and paste this
code in to your database.  Save it as clsTimer.

Option Compare Database
Option Explicit
'
'
Private Declare Function apiGetTime Lib "winmm.dll" _
                                    Alias "timeGetTime" () As Long

Private lngStartTime As Long

'THESE FUNCTIONS / SUBS ARE USED TO IMPLEMENT CLASS FUNCTIONALITY
'*+Class function / sub declaration
Function EndTimer()
    EndTimer = apiGetTime() - lngStartTime
End Function

Sub StartTimer()
    lngStartTime = apiGetTime()
End Sub
'*-Class function / sub declaration


This class is a "timer" of something happening down to a millisecond
resolution.  To use it you simply dim the class and call the StartTimer
method.

Dim lclsTimer as clsTimer

	set lclsTimer = new clsTimer
	lclsTimer.StartTimer

	.
	.
	.some piece of code you want to time
	.
	.
	debug.print lclstimer.EndTimer

To see the advantage of using it over "the competition", suppose you need to
time an inner and outer loop of code...  (or how long a couple of queries
take to run?)

Dim XInner as long
Dim YOuter as long
Dim lclsTimerInner as clsTimer
Dim lclsTimerOuter as clsTimer

	set lclsTimerInner = new ClsTimer
	set lclsTimerOuter as new clsTimer

	lclsTimerOuter.StartTimer
	while YOuter = 1 to 2000
		.
		.lots of code being timed
		.
		lclsTimerInner.StartTimer
		while Xinner = 1 to 15
			.
			.
			.inner loop code being timed
			.
		wend
		debug.Print "Inner Loop: " & lclsTimerInner.EndTimer
		.
		.more code 
		.
	wend
	debug.print "Outer Loop: " & lclsTimerOuter.EndTimer

Because the "data" is stored internally to the class, you can use one or a
thousand instances of this class, anywhere in your code you need to time
something.  You don't have to set up global variables to hold the data, you
don't have to use a collection to hold the various timer values (some
alternatives to a class) etc.  The data for the timer is with the timer
class instance.  The variable holding the class instance is where the timing
occurs.  

Can you do this another way?  Of course but it isn't clean and elegant.  The
alternatives require storing the "time" somewhere "global" and then indexing
in to get the times (collections or arrays) or setting up a new global
variable for each timer and passing in the variable name or something
similar.

YUK

Classes take a little more code to set up (the DIM and the SET
(instantiation)), but where they make sense they will provide a much cleaner
program.  The timer is about the simplest useful class I have ever run into.
Most classes have many variables holding data and many methods for
processing.  But start simple.  Use the timer, learn how to Dim and Set a
class pointer, how to call methods etc.  Once you understand that then move
on.

John W. Colby
www.ColbyConsulting.com 

Contribute your unused CPU cycles to a good cause:
http://folding.stanford.edu/

-----Original Message-----
From: dba-tech-bounces at databaseadvisors.com
[mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Dan Waters
Sent: Wednesday, March 02, 2005 9:39 AM
To: 'Discussion of Hardware and Software issues'
Subject: RE: [dba-Tech] C++ to vb.net conversion


John,

In my programming career, I've probably written 300,000 lines of code, but
none of it in classes.  And you're probably rolling your eyes about now!

Do you have a very simple example of a class, or have a tutorial somewhere
of how to create one?

I am also a single programmer, and want to at least know about this tool so
I can pick it up when appropriate.

Thanks!
Dan Waters
ProMation Systems