hi,
I understood why it did not seem to work .AutoHeigthRows.
The visibility (.ColVisible) and the width of the columns (.ColWidth) must absolutely precede .AutoHeigthRows (or .AutoHeigthRow)
I suppose that to adjust the height of the rows after changing the width of the columns it was necessary to invoke the ColWidthChanged event and then reapply .AutoHeigthRows
and repeat .AutoHeigthRows after every variation of .ColVisible attribute.
thank you