How to Separate the DAL Layer and BLL Layer in a a C# application

Link to Class diagrma Layering
Link to Class Diagram Mail System.
NClass 2.0 or higher is needed to read the file.  NClass Website

In this article we are going to discuss how to separate the Data Access Layer (DAL) form the Business Logic Layer (BLL) using

1) The Abstract Factory Pattern
2) The Model Provider Pattern
3) Reflections


On the Class Diagram Mail System you will find many notes on how to separate the BLL from the DAL
I will first comment on the Class diagram you will find on the link. After I will develop an applicaton. This is a working in progress. As usual if you have any suggestion or improvement, just add a comment.

Parsing an XML file using C#

Link to the Code (VS 2008)


I will show you here two pieces of code in C# that will let you parse the Products.XML into a List object.
The first one makes use of the System.XML namespace, while the second use System.XML.Linq one.
The Linq code is pretty amazing, it is so simple I will not even comment it. I managed also to include a "where" clause to filter the output.

Developing COM exposed classes in C#

Press  here to download the template. CSharp_Com_Class.zip will be downloaded.
For some code example see this  post

Here you can find a series of notes I took as reminders to develpod a COM Class in C#.

I will put it here just as a reference, I hope I will have more time in the future to show you a full example.
You can also find here a C# template you can use to start develop C# COM exposed class. You can delete all the comments out of it. I just add them there for my reference.



To install the template in your VS2008 you need first to find out where they are stored.
To do this, go to File, Export Template. After a few click you should find out where your exported templates
are stored
On my PC for example, they are store here
C:\Users\PP\Documents\Visual Studio 2008\My Exported Templates\WFA01.zip

Once you know this path, just copy the CSharp_Com_Class.zip in the following directory.
You must copy the .zip file. Do not unzip them.

C:\Users\PP\Documents\Visual Studio 2008\Templates\ItemTemplates\Visual C#.

If things go well (and it took me sometime to figure out how to do it) you should have a new template in your
Add New Item, Visual C# Item

UDFs for Excel in VSTO

VSTO does not support yet the introduction of UDFs, which is a kind of crazy!
However there are few work around.

Windows 7 run command...

Where has the Run command gone in Windows 7?

You need to add it.
This are the steps

VSTO "Excel Disigner Could Not Be Activated" error

After Installing VSTO on my PC, and trying our my first "Code Behind" project, I could not have access to the Excel designer. No controls were displayed in the Control toolbox and I could not any button or any type of control on the excel worksheet I was working on
The error message was a pretty scary one

"Excel Designer Could Not Be Activated"

After a bit of diggin on google I found this Post on the msdn forum, which helped me out sort the problem.

Office 2003, PIA Installation guidelines for .NET platform

In case you have problem getting the Primary Interop Assembly (PIA) working fine with your .NET Visual Studio platform, just check this link.

Installing the PIA for Office 2003