Again, the documentation spells out everything you want. Now granted, ListBox contains lots of properties/methods/events, so it’s a lot to digest, but I recommend reading through it all to get better aquainted with it. Usually, something you read will spark an idea you hadn’t thought of.
So it looks like what you’re wanting to do is fill the cells with an incrementing number (which is not “drawing”, that’s another feature/function). Note that you usually define the number of columns in the Layout editor and then add rows in code. But both can be done either way if needed.
Some simple examples of the usual way are below.
(use the “preformatted text” option when posting actual code here - select the text and click the </> toolbar button)
//the following assumes the listbox is already configured with 7 columns (0-6),
//but is currently empty (contains no rows)
Dim ContaGiorni as Integer = 1
For r As Integer = 0 To 6
Calendario.AddRow() //you could include all the row's values here
For c As Integer = 0 To Calendario.LastColumnIndex
Calendario.CellValueAt(r, c) = ContaGiorni.ToString
ContaGiorni = ContaGiorni + 1
Next
Next
Note that cells of a ListBox can only accept a string, so anything else has to be converted first (and converted back if reading the cells).
Here is another way where the ListBox already contains data:
//the following assumes the listbox already contains all the rows & columns needed
//so it just replaces the contents of all cells
Dim ContaGiorni as Integer = 1
For r As Integer = 0 To Calendario.LastRowIndex
For c As Integer = 0 To Calendario.LastColumnIndex
Calendario.CellValueAt(r, c) = ContaGiorni.ToString
ContaGiorni = ContaGiorni + 1
Next
Next
