Architecture Question Business Layer

[hans]

Hi!
I am new to .NET (coming from Java). We have to implement a desktop
application which extracts data from a database, does some analysis,
filtering etc. and displays the results.
I have noticed that in .NET applications Windows widgets like the
DataGrid are often directly bound to a DataSet Object. For me this
means essentially a 2 tier architecture instead of a 3 tier
architecture. I am used to seperating the application into 3 tiers:
Presentation, Business, Persistance. The real world objects are
representated by simple data classes (like customer, order etc.) which
are passed thru these tiers.

Are there any whitepapers out there how to implement a 3 tier
architecture under .NET?
How would be the mapping of DataSet to data objects be done? Are there
frameworks out there which can automate this task?
Can widgets like the DataGrid be bound to say an array of Order
objects?

 

[John Keers]

Hi Hans,

This is not really an answer to your question but it may help.

We have just implemented a multi tier application that retrieves data from
an sql server. Our application is a windows forms app that downloads data
through a communications layer ( dll on the client) through a "xml web
service" (situated on a web server) through a business layer (another dll)
then onto a data layer (yet another dll) which finally talks to the
database.
We find this kind of architecture very flexible that allows us to seperate
the presentation from the business from the data. It works for us anyway.
You didn't say if you were working over the internet or just standalone, if
its the internet then my reccomendation would be to look at web services,
ther are plenty of articles ( http://www.codeproject.com/cs/webservices/ )
is always pretty good for a starter. If you are developing a standalone then
you can still use the same approach just without the web service (as we have
also done) quite simple the communications layer talks directly to a
business layer on the server and so on....

Hope this was of some help?

 

[Guest]

Hans,

You can bind collections of objects to a DataGrid (and any other databound
controls). I do this by creating a new class for each of my business objects
with the suffix "Collection" or "s". For example, if you have a User class,
I would create another class called either "UserCollection" or "Users". This
new class must inherit System.Collections.CollectionBase

The collection object can then be bound to the DataGrid.

Here's an article... http://www.csharphelp.com/archives/archive89.html

Hope this helps!

-Paul