//methods中添加方法
onPullDownRefresh() {
			        console.log('refresh');
			        this.timer = setTimeout(() => {
						uni.stopPullDownRefresh()
			        }, 1000);
			    },
			    beforeDestroy() {
			        clearInterval(this.timer);
			    },

//pages.json



{
			"path": "pages/tabbar/cart/index",
			"style": {
				"navigationBarTitleText": "购物车",
				 "enablePullDownRefresh": true
			}
		},