小程序唤起支付

名称：my.tradePay
类型：小程序接口
功能：支付订单字符串通过小程序方式唤起支付

注意：接口为通用接口，该场景下，请参考如下编写：

<pre class=" language-js" style="box-sizing: border-box; font-size: 12px; font-family: Consolas, Monaco, &quot;Andale Mono&quot;, &quot;Ubuntu Mono&quot;, monospace; margin: 0.5em 0px; overflow: auto; color: rgb(102, 102, 102); background: rgb(247, 247, 247); text-shadow: rgb(255, 255, 255) 0px 1px; text-align: left; white-space: pre; word-spacing: 0px; word-break: normal; overflow-wrap: normal; line-height: 1.5em; tab-size: 4; hyphens: none; padding: 0px; display: block; max-width: 100%; border-radius: 4px; border: 1px solid rgb(238, 238, 238); position: relative; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; widows: 2; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">`my.tradePay({
  orderStr: 'myOrderStr', //完整的支付参数拼接成的字符串，从服务端获取
  success: (res) => {
    my.alert({
      content: JSON.stringify(res),
    });
  },
  fail: (res) => {
    my.alert({
      content: JSON.stringify(res),
    });
  }
});