gridview 设置某行控件不可见

 　　　　　　　　　　　((DropDownList)e.Row.FindControl("ddlRc")).Visible = false;
                    ((Button)e.Row.FindControl("btnApprove")).Visible = false;
                    ((Button)e.Row.FindControl("btnReject")).Visible = false;
                    ((TextBox)e.Row.FindControl("txtIRemark")).Visible = false;
                    ((Label)e.Row.FindControl("labBuyCon")).Text = string.Empty;