Question

I am able to select a single cell from a data grid view but I am trying to see if it would be possible for me to select multiple cells at once and use that data. to create a chart using C#

Answer 1

You can try to select DataRow, this DataRow contains Cells property

 var cells = DataGridView.Rows[index].Cells;

Code Sample

    public DataControlFieldCell GetCellByName(GridViewRow Row, String CellName)
    {
        foreach (DataControlFieldCell Cell in Row.Cells)
        {
            if (Cell.ContainingField.ToString() == CellName)
                return Cell;
        }
        return null;
    }

In order to permit multi select , you define DataGridView.MultiSelect property

Link : http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.multiselect.aspx

You can also use

DataGridName.SelectionMode = DataGridViewSelectionMode.CellSelect

Link : http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.selectionmode.aspx