Passing data from DAL to BLL to PL using vb.net in winforms
Posted on 2010-09-15
I am designing a desktop app using VS 2008 and MS Access. It is going to be a 3-tier app. I am experimenting different things that my app will need. For example,
My Form(PL) has this combobox. UI will call BL to get All the Product Categories, assign Combobox.Datasource= BL.GetCategories(list or array())
Product Categories has attributes like Category_Name, Category_ID, Category)Type etc.
BL will ask the DAL to get the categories from the Access database. Can I use arrays or lists to be passed to BL? How do I pass objects (class)
I want to keep these three layers as independent as possible, so in future we make it Web based, my PL will only change. if we use SQL server instead of Access, only DAL will change. If we change business rules, only BLL will change.
I have been searching the net for last two days,but cannot find sample code for VB.NET AND Winforms, or simple enought to understand.
So the question is : how do I implement DA so that it passes class or list or array
How does the BLL pass this data to PL
, And in PL(form level) how do i populate Combobox(Dropdown List) using it's datasource property? This combobox will have Category Name as display Item and Category_Id as tag(? )(Itemdata in vb6 world).
This will be my basic building block and from this, I can build more complicated routines.
I will greatly appreciate if you can provide me a small but complete sample code in vb.net. for Winforms . Thanks in advance.