Question

I want to pass my listbox items down to my business layer.

//From Save click event
var toBusiness = new List<string>();

foreach (var item in lbProducts.Items)
{
    toBusiness.Add(item.ToString());
}

Is this the way to do it?

Answer 1

I would thing that the items came from the business layer, correct? So you just need to pass something to the business layer that is non-gui that allows the business layer to recognise them. If your item has a unique ID then you could just pass a List or array of the unique ID, otherwise just pass an array of the items.

var items = lbProducts.Items.OfType<MyItemType>().ToArray()
myBusinessLayer.DoSomething(items);

or

var ids = lbProducts.Items.OfType<MyItemType>().Select(i => i.ID).ToArray()
myBusinessLayer.DoSomething(ids);