Hi,

I would think that should work.  I have actually done it with code on the server.  Could you try this?

protected void WebHierarchicalDataGrid1_GroupedColumnsChanged(object sender, GroupedColumnsChangedEventArgs e)

    {

            if (e.Action == GroupByChangeAction.Group)

                foreach (GroupedColumn col in e.GroupedColumns)

                    e.Band.Columns[col.ColumnKey].Hidden = true;

            if (e.Action == GroupByChangeAction.Ungroup)

                foreach (GroupedColumn col in e.GroupedColumns)

                    e.Band.Columns[col.ColumnKey].Hidden = false;

    }

    protected void WebHierarchicalDataGrid1_RowIslandDataBound(object sender, RowIslandEventArgs e)

    {

        for (int x = 0; x < e.RowIsland.Columns.Count; ++x)

        {

            if (x < e.RowIsland.Band.Columns.Count)

                e.RowIsland.Columns[x].Hidden = e.RowIsland.Band.Columns[x].Hidden;

        }

    }

-Dave

Thanks for your answer AgentD5.

Here is the code i'm using to hide the column:

<script type="text/javascript">

    function changeGroup(e, f) {

        var grid = $find("MyGrid");

        var parentGrid = grid.get_gridView();

        parentGrid.get_columns().get_columnFromKey(f.get_effectedColumn().get_columnKey()).set_hidden(hidden);

    }

</script>

I call this function on the GroupedColumnsChanging client method.