Paypal网格视图仅发送第一列而不是每列

Question

我有一个按钮，用于将已添加到网格视图中的所有项目发送到付费网站。目前，它只将第一列项目发送到paypal网站。例如，我在购物车中有项目A和项目B.只有项目A信息将进入paypal网站，而不是项目B.请帮助我。谢谢，最诚挚的问候！：D

网格视图代码：

        <asp:GridView ID="gv_CartProduct" runat="server" AutoGenerateColumns="False" onRowCommand="gv_CartProduct_OnRowCommand">
        <Columns>
        <asp:TemplateField HeaderText="Title">
            <ItemTemplate>
                <asp:Label ID="lbl_title" Text='<%# Eval("title") %>' runat="server"></asp:Label> 
            </ItemTemplate>
        </asp:TemplateField>
           <asp:TemplateField HeaderText="Image">                   
                    <ItemTemplate>
                        <asp:Image ID="imgPreview" ImageUrl='<%# Eval("image")  %>' runat="server"
                            Height="80px" Width="80px" />
                    </ItemTemplate>
                </asp:TemplateField>

        <asp:BoundField DataField="price" HeaderText="Price" DataFormatString="{0:0.00}" />
       <asp:TemplateField HeaderText="Quantity">
       <ItemTemplate>
            <asp:TextBox ID="tb_quantity" runat="server"  CommandArgument='<%# Eval("title")%>' Text='<%# Eval("qty") %>' ></asp:TextBox>
        </ItemTemplate>
         </asp:TemplateField>
        <asp:TemplateField>
        <ItemTemplate>
        <asp:LinkButton ID="btn_delete" runat="server" Text="Delete" CommandName="deleterow" CommandArgument='<%# Eval("title") %>' OnClientClick="return confirm('Do you want to delete product?');"  ></asp:LinkButton>
        </ItemTemplate>
        </asp:TemplateField>
      </Columns>
        </asp:GridView>

btn_checkout_Click代码：

 protected void btn_Checkout_Click(object sender, EventArgs e)
        {
            CartBLL cbll = new CartBLL();
            Cart c1 = new Cart();
            username = (string)(Session["username"]);


            foreach (GridViewRow row in gv_CartProduct.Rows)
            {
                if (row.RowType == DataControlRowType.DataRow)
                {

                    string qtystring = ((TextBox)(row.FindControl("tb_quantity"))).Text;
                    string title = ((Label)row.FindControl("lbl_title")).Text;
                    int amount = Convert.ToInt32(row.Cells[2].Text);
                    string amountInString = amount.ToString();



                    string redirectUrl = "";

                    //Mention URL to redirect content to paypal site
                    redirectUrl += "https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_xclick&business=" + ConfigurationManager.AppSettings["paypalemail"].ToString();

                    //First name I assign static based on login details assign this value
                    redirectUrl += "&first_name=" + username;

                    //Product Name
                    redirectUrl += "&item_name=" + title;

                    //quantity
                    redirectUrl += "&quantity=" + qtystring;

                    //Business contact paypal EmailID
                    redirectUrl += "&business=121366S-facilitator@mymail.nyp.edu.sg";

                    //price if any, or available or using shopping cart system
                    redirectUrl += "&amount=" + amount;



                            //If transactioin has been successfully performed, redirect SuccessURL page- this page will be designed by developer
                redirectUrl += "&return=" + ConfigurationManager.AppSettings["SuccessURL"].ToString();

                //If transactioin has been failed, redirect FailedURL page- this page will be designed by developer
                redirectUrl += "&cancel_return=" + ConfigurationManager.AppSettings["FailedURL"].ToString();

                Response.Redirect(redirectUrl);
               }
            }
        }