protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e) 
    { 
    if (e.Row.RowIndex != -1) 

                e.Row.Attributes.Add("onmouseover", "this.style.backgroundColor='#bfd4e6'"); 
                e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor='#efefef'"); 
                string id = e.Row.Cells[1].Text; 
                e.Row.Attributes.Add("ondblclick", "window.open('2.asp?pipe_num="+id+"')"); 
        }     } 无法得到id???????id为空?????