merging two datagridview columns into one new column

Question

i want to merge two datagridview columns into one new column.

i first change Visible property of two col to false, then i try to add new col which that value must be

Answer 1

Try this (it works for me):

reportResultForm.dgvResult.Columns.Add("newColumn", "New Column");
        foreach (DataGridViewRow row in reportResultForm.dgvResult.Rows)
        {
            string height= row.Cells["Height"].Value.ToString();
            string width= row.Cells["Width"].Value.ToString();
            string formattedCol= string.Format("{0} per {1}", height, width);
            row.Cells["newColumn"].Value = formattedCol;
        }