uniapp实现微信公众号支付的方法步骤

callPay: function(response) {
				if (typeof WeixinJSBridge === "undefined") {
					if (document.addEventListener) {
						document.addEventListener('WeixinJSBridgeReady', this.onBridgeReady(response), false);
					} else if (document.attachEvent) {
						document.attachEvent('WeixinJSBridgeReady', this.onBridgeReady(response));
						document.attachEvent('onWeixinJSBridgeReady', this.onBridgeReady(response));
					}
				} else {
					this.onBridgeReady(response);
				}
			},
			onBridgeReady: function(response) {
				let that = this;
				if (!response.package) {
					return;
				}
				WeixinJSBridge.invoke(
					'getBrandWCPayRequest', {
						"appId": response.appid, //公众号名称，由商户传入
						"timeStamp": response.timestamp, //时间戳，自1970年以来的秒数
						"nonceStr": response.noncestr, //随机串
						"package": response.package,
						"signType": response.signType, //微信签名方式：
						"paySign": response.sign //微信签名
					},
					function(res) {
						if (res.err_msg === "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。
							uni.showLoading({
								title: '支付成功'
							});
							setTimeout(function() {
								uni.hideLoading();
								uni.redirectTo({
									url: '../member/orderdetail?id=' + that.id
								});
							}, 1000);
						} else {
							uni.hideLoading();
						}
						WeixinJSBridge.log(response.err_msg);
					}
				);
			},