My gridDataControl is set with ColumnSizer=Auto in XAML and it initially displays columns sized according to header / cell size as expected.
But when user picks new columns to display, I clear out the VisibleColumns and add new ones in .cs code.
But then it seems the 'Auto' format is lost, because all the columns display with a fixed size that is much larger than necessary.
How do I restore Auto column sizing in .cs code ?