pay() {
      if (!this.selIndArr.length) {
        Toast({
          message: '请先选择要支付的订单！',
          duration: 1000,
          forbidClick: true
        })
        return;
      }
      let orderNumArr = []
      for (let i = 0; i < this.selIndArr.length; i++) {
        orderNumArr.push(this.list[this.selIndArr[i]].orderId)
      }
      Toast.loading({
        mask: true,
        duration: 0, // 持续展示 toast
        forbidClick: true,
        message: '发起支付中...'
      });
      let params = {
        orderNos: orderNumArr.join()
      }
      this.$api.payOrder(params).then(res => {
        if (res.code == 10000) {
          Toast.clear();
          let param = res.data.jsRequstParam
          this.onBridgeReady(param)
          if (typeof WeixinJSBridge == "undefined") {
            if (document.addEventListener) {
              document.addEventListener('WeixinJSBridgeReady', this.onBridgeReady(param), false);
            } else if (document.attachEvent) {
              document.attachEvent('WeixinJSBridgeReady', this.onBridgeReady(param));
              document.attachEvent('onWeixinJSBridgeReady', this.onBridgeReady(param));
            }
          } else {
            this.onBridgeReady(param)
          }
        }
      })


    },
    onBridgeReady(param) {
      let that = this;
      WeixinJSBridge.invoke(
        'getBrandWCPayRequest', {
        "appId": param.appId,     //公众号名称，由商户传入     
        "timeStamp": param.timeStamp,         //时间戳，自1970年以来的秒数     
        "nonceStr": param.nonceStr, //随机串     
        "package": param.pack,
        "signType": param.signType,         //微信签名方式：     
        "paySign": param.paySign //微信签名 
      },
        function (res) {
          console.log('onBridgeReadyRes==', res);
          if (res.err_msg == "get_brand_wcpay_request:ok") {
            console.log('get_brand_wcpay_request:ok');


            // 使用以上方式判断前端返回,微信团队郑重提示：
            //res.err_msg将在用户支付成功后返回ok，但并不保证它绝对可靠。所以要检测订单是否支付成功
            that.checkPay(param.outTradeNo, 0)
          }
          else if (res.err_msg == "get_brand_wcpay_request:cancel") {
            Toast('取消支付！');
            //window.history.back(-1);
            }
        });
    },