Not exactly. When you create a list (dropdown/listbox) all the items that are in it got stored in the page's viewstate. That's why if you were to have one line (listbox.Items.Add(...)) in page_load by itself, you'd see your list increase by one item with each postback.

So the list object is restored from the viewstate when you post back. Then the control figures out if you selected a different item by analyzing which item WAS selected (also in viewstate) and which is NOW selected (from Request.Form). So you then remove the selected item and the control save's its viewstate (now short one item) and redraws. Then the whole process starts over again. It all hinges on that hidden viewstate field.

I must admit, the way they have created event-driven, state-retaining forms on a web platform was quite creative.

Peter

Just curious... what books did you learn from?

I learned a lot just from playing around. Much of the rudimentary programming theory I got at college. Most of the .Net knowledge I got from experimenting and reading the MSDN articles and help files. I do have the "Beginning ASP.Net w/ VB.Net v1.0" (Wrox ISBN: 1-861007-33-7). I was attempting to read it cover to cover, but only have gotten halfway thru. But I have referenced various bits of that. For the most part it's trial and error.

Peter

Hi,
  I am trying to generate a list of random numbers from a string array, but it keeps giving me repetitions in some instances. How do i prevent the array from generating the same random number twice?
Thanks. here is what i used and didn't work.


Dim namesArray() As String = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"}
        Dim intRandom As Integer = Int(Rnd() * 10 + 1)
        Return namesArray(intRandom - 1)

You need to either remember what you've already chosen or remove what you've already chosen from the select group.

Are you going to have to remember what's been selected between page hits or are you selecting a series of random values at once? If you need to remember between page hits it's a bit harder.

Peter