[dba-VB] C# serialization

You can build a typed dataset on an xml file John.  Doesn't require a
database.

Charlotte 

-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of jwcolby
Sent: Tuesday, October 13, 2009 8:38 AM
To: Discussion concerning Visual Basic and related programming issues.
Subject: Re: [dba-VB] C# serialization

 >Do these classes inherit typed datasets?

Nope, no connection to a database.

The original assignment was to build a grade calculator where you simply
input a list of grades. 
There are three types of grades, each with a different weight (Tests -
40% of grade, Labs - 50% of grade and DL 10% of grade).

There is no requirement to do anything more than the above, calculating
a total count of each grade type, sum of each type, average of each type
and weighted average of each type, and then the same calculations for
the totals.

In order not to be bored to death, and with the approval of the
instructor, I expanded the assignment to include using classes and
collections.  I store each grade in an instance of clsGrade. 
  I store all of each TYPE of grade in an instance of clsGrades (plural)
which contains a generic collection into which the instances of clsGrade
are inserted.  This collection is strongly typed so that it can only
accept clsGrade objects.

Each instance of clsGrades (plural) is inserted into a sorted list in
clsCalculator, keyed on GradeType (keyed on the string "Test", "Lab" or
"DL").  In the main form there is a combo with three grade type strings
("Test", "Lab" and "DL") which when selected is passed in to
clsCalculator which indexes into the collection to access the correct
instance of clsGrades.  Adding new grades, deleting grades and updating
existing grades is all done on the selected instance of clsGrades.

So...

clsCalculator - interfaces to the form and has a sorted collection
holding three instances of...
clsGrades - contains a strongly typed generic collection holding
multiple instances of ...
clsGrade - contains each grade.

clsGrades performs the calculations to count (collection.count), sum,
average and weighted average all of the grades contained within.

clsCalculator requests the various computed values from the three
instances of clsGrades and performs the calculations to create an
overall Count (sum of clsGrades.Count), Sum (sum of clsGrades.Sum),
Average, weighted sum etc.

Now...

I want to write the grades in each clsGrades instance to a single file,
then read it back in again. 
  Persist the grades to disk.  I have no requirement to persist the data
to disk, I simply want to do so.

Please please please do not suggest a "better way" for doing the
assignment, it is all written and functions exactly as you would expect
it to work.  You may of course enlighten me on different options, but I
will not be rewriting the core assignment at this point.

This was just a homework assignment and it is in fact finished.  If I
can persist it great, if not that's OK too.  I have learned a lot and
thought I might learn how to do the persist thing, streams,
serialization (if that is used) etc.  Even classes and collections are a
"next semester" thing so I am ahead of the curve at this point.

John W. Colby
www.ColbyConsulting.com


Charlotte Foust wrote:
> John,
> 
> I'm not sure I understand what you're doing.  Do these classes inherit

> typed datasets?  If so, the parent class can easily return a child 
> class that already contains a typed dataset of child records.  You 
> don't actually need collections for that.  In that case, grade 
> wouldn't need to be a class (although it could be, I just don't see 
> any need).  The
> 
> Charlotte Foust