React操作真实DOM实现动态吸底部的示例

componentDidMount() {
 this.changeFixed()
}
//計算高度
changeFixed(){
 //getDOMNode
 const layoutNode = document.querySelectorAll('.page-layout')[0];
 const orderPriceNode = document.querySelectorAll('.test-price')[0];
 window.addEventListener('scroll', function (e) {
 const windowInnerHeight = window.innerHeight;
 const layoutNodeHeight = layoutNode.offsetHeight;
 //滚动超出视野距离
 let scrollTop = window.pageYOffset|| document.documentElement.scrollTop || document.body.scrollTop;
 const distanceBottom = layoutNodeHeight - scrollTop - windowInnerHeight;
 //120的时候吸底
 if(distanceBottom <= 120){
 orderPriceNode.classList.remove('fixed');
 }else{
 orderPriceNode.classList.add('fixed');
 }
 })
}