九九发卡的支付系统采用的完全服务端回调技术，客户端的所有数据不会参与到服务端的运行，以及自动发卡等技术，客户端都完全不参与，客户端打开订单后，就算把网页或浏览器完全关闭，支付后还是照常会给客户发卡，完全封闭式的发卡技术，完全不用担心别人使用fd之类的抓包工具修改数据。

订单原理

订单创建的原理是客户发起订单请求，服务端进行订单创建，并且拉取预备好的二u维码（固定金额），给用户支付，当该二维码正在支付的时候，其他人下单是无法拉取到该二维码的，所以不用担心资金混乱问题，并且当你没有该金额的二维码，系统会自动通过你个人资料预备好的二维码（手动输入金额支付），然后生成二维码给用户扫码，用户支付完成后，监控端监听到金额然后提交到服务端并且处理订单，然后服务端自动发卡。(The principle of order creation is the customer initiated order request, the server creation order, and pull the two U dimensional code ready (fixed amount), to the user to pay, when the two-dimensional code is paid, the others order is unable to pull to the two-dimensional code, so do not worry about money problems. And when you do not have the amount of two-dimensional code, the system will automatically through your personal data for the two-dimensional code good (manual input amount, and payment) to generate a two-dimensional code scan code to the user, users pay after the completion of the monitoring terminal monitor the amount and then submitted to the server and then the server processing orders, automatic card.)