VUE 实现监听滚动事件，实现数据懒加载

methods: {
    // 获取滚动条当前的位置
    getScrollTop() {
        let scrollTop = 0
        if (document.documentElement && document.documentElement.scrollTop) {
            scrollTop = document.documentElement.scrollTop
        } else if (document.body) {
            scrollTop = document.body.scrollTop
        }
        return scrollTop
    },
    // 获取当前可视范围的高度
    getClientHeight() {
        let clientHeight = 0
        if (document.body.clientHeight && document.documentElement.clientHeight) {
            clientHeight = Math.min(document.body.clientHeight, document.documentElement.clientHeight)
        } else {
            clientHeight = Math.max(document.body.clientHeight, document.documentElement.clientHeight)
        }
        return clientHeight
    },

    // 获取文档完整的高度
    getScrollHeight() {
        return Math.max(document.body.scrollHeight, document.documentElement.scrollHeight)
    },
    // 滚动事件触发下拉加载
    onScroll() {
        if (this.getScrollHeight() - this.getClientHeight() - this.getScrollTop() <= 0) {
            if (this.status <= 5) {
                this.status++;
                // 调用请求函数
                this.axios.get('url'
                ).then(data => {
                    console.log(data)
                });
            } 
        }
    },
}

mounted() {
    this.$nextTick(function () { // 解决视图渲染，数据未更新
        window.addEventListener('scroll', this.onScroll); 
    })
}