data{
oldScrollTop: 0, //记录上一次滚动结束后的滚动距离
scrollTop: 0 ,// 记录当前的滚动距离
}
watch: {
scrollTop(newValue, oldValue) {
setTimeout(() => {
if(newValue == window.scrollY) { //延时执行后当newValue等于window.scrollY,代表滚动结束
console.log('滚动结束');
this.oldScrollTop = newValue; //每次滚动结束后都要给oldScrollTop赋值
this.tran_flag=true;
};
}, 200); //必须使用延时器,否则每次newValue和window.scrollY都相等,无法判断,20ms刚好大于watch的侦听周期,故延时20ms
if(this.oldScrollTop == oldValue) { //每次滚动开始时oldScrollTop与oldValue相等
console.log('滚动开始');
this.tran_flag=false;
}
}
},
methods: {
handleScroll() {
window.addEventListener('scroll', () => {
this.scrollTop = window.scrollY;
})
},
}
beforeDestroy() {
window.removeEventListener('scroll',() => {
this.scrollTop = window.scrollY;
}); //离开当前组件别忘记移除事件监听哦
}