how can I add a new row to datagrid at every button click

Question

I want to add new row to gridcontrol at every button click. I tried many ways but no success. I am sending my code below. 

private void B_Click(object sender, EventArgs e)

{

Button bt = (Button)sender;

 int productId = (int)bt.Tag; AddProductDataContext db = new AddProductDataContext(); 

decimal Quantity; 

decimal.TryParse(txtCalculator.Text, out Quantity);           

gridControl1.DataSource = from inv in db.Inventories where inv.RecId == productId       

                            select new {                                        

inventoryName = inv.InventoryName, 

Quantity, Total = Quantity * inv.InventoryPrice };          

gridView1.AddNewRow();         

gridView1.UpdateCurrentRow();

}

Is there anyone to help me out there for the above? Thanks in advance for your precious replies.