string trade_no = Request.QueryString["trade_no"];              //支付宝交易号
                string order_no = Request.QueryString["out_trade_no"];            //获取订单号
                string total_fee = Request.QueryString["total_fee"];            //获取总金额
                string subject = Request.QueryString["subject"];                //商品名称、订单名称
                string body = Request.QueryString["body"];                      //商品描述、订单备注、描述
                string buyer_email = Request.QueryString["buyer_email"];        //买家支付宝账号
                string trade_status = Request.QueryString["trade_status"];      //交易状态

                if (Request.QueryString["trade_status"] == "TRADE_FINISHED")
                {
                    this.ret_lab1.Text = order_no;
                    this.ret_lab2.Text = subject;
                    this.ret_lab3.Text = total_fee;
                    this.ret_lab4.Text = trade_no;
                 }
哪位大哥帮看下，地址栏的返回参数是有的，但就是赋值不到lLabel控件上