Visual Studio 2013 - New Project

Question

Hi
Many years ago I wrote a VB6 program for school students for diet analysis in terms of energy and a range of vitamins and minerals.  It drew comparisons against the national guidelines.  Results were tabulated, graphed and output provided in Word
and Excel files.  The VB6 program used an Access database containing about 850 foods. It has been used by quite a few schools and appears to always be used across a network.
My intention is to re-write the whole program in Visual Studio 2013 using Visual Basic code.  I intend to refresh the whole program and add a wider range of foods and update the comparisons using the latest national guidelines and food label formats.
This will be my first attempt at Visual Studio and I intend to use a Windows Forms Application approach.  The data used is "static" - it does not change it is simply a "read only" file - get the data, multiply for mass and add up each
category (energy, vitamins and minerals).  It is a "file of data" rather than a true database.  In reality a 1000 food data file should only be about 200 Kbytes.  As an Excel file it is only 150Kbytes but as an Access file it is bloated
up to a 550Kbyte file.
The program is not sophisticated, so, should I be using a WPF Application or a Window Forms Application?  The WFA just feels a bit more familiar than a WPF.  Also, the program is intended for loading onto a network at some schools or on a stand-alone
computer.
My greatest concern is about the choice of approaching the data.  A "true" database is not needed because the data is simply for about 1000 rows of food each with about 20 columns of data (numeric and text).  The Access file is simple
but I could create an mdf file (I think) but would that be an advantage?  With the Access data I appear to have loaded the file and created a DataAdapter and I have experimented with GetData() which works.  My attempts to use ExecuteReader() failed
completely.  Is there a better approach?  such as SQL "DataTable.Rows(RowPosition)(“column name")”??  It seems a very sophisticated method for a small file of data.
The Access Database that I have experimented with in VS2013 appears to use Jet Drivers???? which proved to create a few problems for installations in the past.  Should I be using an mdf file approach??  I will need to distribute the data in a "resx"
file.  I could use SQL Server Management Studio (free download) and then use VS2013 to read the Access file and build a new mdf database.....
I am not convinced that I have the best solution.  Any comments and suggestions would be very greatly appreciated.
Many thanks for reading this far.
Winchestermili
Winchestermili

Answer 1

Frank
Looking good!  The "attachment" to a new project worked first time.
I can see all the new Classes by hovering a pointer over the "declarations" above "Public Class Form1"
Seems to access the VBNetForum URL quite quickly using a high speed BB connection.
I am greatly looking forward to the next stage...........
Regards
Keith
Winchestermili
Keith,
I intentionally truncated that post with “let me know when you’re that far along” simply because it’s very easy to get lost
with a concept that’s new. This isn’t as different as you might think though – you’ve been using a database, and now you’ll be using instances of a class (various ones).
Over the years here, I’ve seen many times where people use databases because they assume “that’s the only way to do it”. The
“it” actually being encapsulation.
Encapsulation
is what they need and certainly a database provides that (and a lot more), but it’s not the only way it can be done.
Think about this a bit: A DataRow encapsulates the related data for whatever it is. For example maybe it’s a person’s data –
you’d want to keep the person’s first name, surname, and things like that all together because it defines something related to that one person. You then have a collection of those DataRows in a DataTable.
In much the same way, what I have here is similar: Instead of a DataRow, I’m using instances of a class. Instead of columns
in a DataRow, I’m using properties of the instance, and instead of a DataTable, I’m using a List(Of Class).
…the concept is identical.
Classes are a means of building an object in OOP. In and of itself, it’s really just a template or a blueprint (overused metaphor).
Deborah Kurata put it best, in my opinion, when she said that a class is like a cookie-cutter and the objects created are cookies. You eat the cookies, not the cookie-cutter!
A class works that way exactly: You can’t “consume” a class; you consume the objects (instances) created by them and in this
case, like a DataTable housing DataRows, I’m storing them in a very specific type of collection known as a List(Of T).
I don’t want to get too far adrift about classes and/or OOP here – not that I would mind the discussion – but it’s a new concept
to you and it’s easy to get confused about what’s doing what. I’ll get more to the specifics next.
That entire class library is the data layer; it doesn’t work with controls of any sort, only the data.
That said though, in the following I’ll explain how controls can be ‘assisted’ by the methods in the classes.
The main class in this is the one called “FoodComposition”. That one is only barely started – the
only
method in it so far is an overloaded way to add a new instance to a list of them.
Two of the classes are really just ‘supporting classes’ – those being the ones called “FoodCategory” and “LabelNote”. Don’t
get me wrong here, they do have methods in them (with more to be added), but you won’t too much be working with those in the user’s program – you will in the program that I’ll create for you to add/modify/remove* and so on, but for now let’s set those two
aside.
*  The fact that these are “supporting” classes, I have it set up such that you cannot remove an instance of those if there’s
a reference to them in FoodComposition. If you want to see where/how I’m doing that, look at the code of the class FoodCategory, for example, and go to line 633, then read the code of that method named “Remove”.
The one class in the bunch which is pretty much self-contained is the one called DietaryReferenceValue (DRV is the name you
used). That one makes for a good topic to explain how I can provide methods which lend a helping hand to your controls but don’t, directly, have anything to do with controls.
I have a method in that class named “GetAllGroupNames” which is a function that returns a string array containing the names
of each instance’s group. That might be used, for example, if you wanted to show a ListBox or a ComboBox to allow the user to select one of the group names:
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles MyBase.Load
Dim url As String = _
"http://www.fls-online.com/VBNet_Forum/12-13-14/NutritionData.xml"
GetNutritonData(url)
ListBox1.Items.AddRange(NutritionData.DietaryReferenceValue.GetAllGroupNames(drvList))
End Sub
So, for example, when the user selects one of them:
Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles ListBox1.SelectedIndexChanged
Try
If ListBox1.SelectedIndex > -1 Then
Dim selectedGroup As String = _
ListBox1.Items(ListBox1.SelectedIndex).ToString
Dim drv As NutritionData.DietaryReferenceValue = _
NutritionData.DietaryReferenceValue.GetInstance(drvList, selectedGroup)
MessageBox.Show(drv.ToString, drv.SexAndAgeGroup)
End If
Catch ex As Exception
MessageBox.Show("An error occurred:" & vbCrLf & vbCrLf & ex.Message, _
"Program Error", MessageBoxButtons.OK, _
MessageBoxIcon.Warning)
End Try
End Sub
As you can see there, I’m using the .ToString method which I have overridden in the class. That’s also part of what I wanted
to discuss: What it gets.
Currently I don’t have much else (other than maintenance routines like adding, removing, renaming) in there; the methods that
you use are methods that I set up – but in the words of Hamlet, “therein lies the rub” … I don’t know what you want!
Give some thought to just what methods you might want to have in there. For example maybe you might want to have a method which
will return the value of one specific nutrient which you specify. I can do that, I just don’t know yet that you want it so it’s not there.
Quite often I’ll also provide what I’m come to call “convenience properties”. For example with the property named “Sodium”,
I might have another property (read-only) named “Sodium_String” which returns a string in whatever format you wanted it to have.
These are things I don’t know that you want and also things which you may not have known can be done, thus this writing. ;-)
The other day I asked about units. It may not be where you want to go with this but I’d also like to offer that we can provide
more granularity to the nutrients themselves. Don’t get me wrong, it’d be an overhaul of what I have right now, but I’ll do it if you want to proceed:
Imagine that we have a class, all by itself, that we call “Nutrients”. At the very least that class would have members like
Name and UnitOfMeasure, but it could have anything else you wanted. An example that comes to mind might be the URL to a page on Wikipedia about it, or maybe a URL to an appropriate image or … whatever you dream of here.
So then when using them in the other classes, “Calcium” would, itself, be an object which has a name (“Calcium”), a unit-of-measure
(maybe “milligram”), and so on.
It’s a lot to take in all at once and even this is something you may want to reread, but do give it thought. Let me know what
methods you want in the classes which will help you in your user’s program.
Still lost in code, just at a little higher level.