listgrid - show column setting

How to hide columns to be shown in a viewport ?

I have a small portal (new Portlet) and added list-grid to it.

Columns of list-grids are dynamic, as of now I see all columns of a data-source applied to list-grid.

I tried calling : resultGrid.setShowAllColumns(false);

but no effect on column displayed, all columns squeezed in small area.