vue获取滚动的scrollTop的值

https://blog.csdn.net/qq_42074075/article/details/99736565

mounted() {
    // let _this=this
    window.addEventListener('scroll', () => {
        let top = document.documentElement.scrollTop || document.body.scrollTop || window.pageYOffset
        console.log(top);
        if (top > 700) {
            this.scrollTag = true;
        } else {
            this.scrollTag = false
        }
    })
}