Cannot implicitly convert System.Eventhandler to System.Window.Form.KeyPressEventHandler :  private void grdPOItems_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
        {
            int colIndex = grdPOItems.CurrentCell.ColumnIndex;
            string colName = grdPOItems.Columns[colIndex].Name;
            if(colName == "Qty" || colName == "Rate")
            {
                e.Control.KeyPress += new EventHandler(CheckKey);
            }
        }

        private void CheckKey(object sender, EventArgs e)
        {
            if (((e.KeyChar < 48 || e.KeyChar > 57) && e.KeyChar != 8 && e.KeyChar!='.'))
            {
                e.Handled = true;
            }  
        }