了解一下微信小程序支付

<view class="container">
    <input type="text" bindinput="getOrderCode" style="border:1px solid #ccc;"  />
    <button bindtap="pay">立即支付</button>
</view>

Page({
  data: {
    txtOrderCode: ''
  },
  pay: function () {
    var ordercode = this.data.txtOrderCode;
    wx.login({
      success: function (res) {
        if (res.code) {
          wx.request({
            url: 'https://www.yourdomain.com/pay',
            data: {
              code: res.code,//要去换取openid的登录凭证
              ordercode: ordercode
            },
            method: 'GET',
            success: function (res) {
              console.log(res.data)
              wx.requestPayment({
                timeStamp: res.data.timeStamp,
                nonceStr: res.data.nonceStr,
                package: res.data.package,
                signType: 'MD5',
                paySign: res.data.paySign,
                success: function (res) {
                  // success
                  console.log(res);
                },
                fail: function (res) {
                  // fail
                  console.log(res);
                },
                complete: function (res) {
                  // complete
                  console.log(res);
                }
              })
            }
          })
        } else {
          console.log('获取用户登录态失败！' + res.errMsg)
        }
      }
    });
  },
  getOrderCode: function (event) {
    this.setData({
      txtOrderCode: event.detail.value
    });
  }
})