I wonder what are the alternatives and the best practices for instance creaation on a standard 3 layer application.
In UI:
-Should i create one BLL object on form load or create instances every time i need to call BLL methods?
In BLL:
-Should i pass a new DAL object in the BLL constructor or i should create the dal in every method?
DAL:
Currently my DAL is traditionally developed using oledb to connect to AS400 and utilizes ado.net to make the needed operations. Every method opens and closes the connection after the completion of the execute command.
-Is this ok? or i should follow something else?
My requirements include the possibility to be flexible in my UI being able to have almost every possible case for UI implementation (web page ,winforms, e.t.c).