说明：  实现原理 无论是支付宝还是微信的收款码，其本质上是一个包含了收款链接的二维码。所以我们的思路是：检测如果是支付宝浏览页面，就给出支付宝的付款链接、如果是微信，就给出微信链接……
(Realization principle Whether it's Alipay or WeChat's collection code, it's essentially a two-dimensional code that contains a receipt link. So our idea is: if the test is Alipay browsing page, it gives the Alipay link of payment, if it is WeChat, it gives the WeChat link...)