react tab居中切换 React实现类似淘宝tab居中切换效果的代码实例
浅夏晴空 人气:0效果
DOM布局
const label = { lettersort: false, paramname: "label", paramid: 0, title: "车源列表筛选项", option: [{ value: 1, text: "全部" }, { value: 2, text: "本地求购" }, { value: 3, text: "精准收车" }, { value: 4, text: "全国收车" }, { value: 5, text: "同行询价" }, { value: 6, text: "可批可售" }, { value: 7, text: "车抵贷款" }, { value: 8, text: "消费贷款" }, { value: 9, text: "商家库容" }, { value: 10, text: "代理合作" }, { value: 11, text: "过户转籍" }, { value: 12, text: "寻车拖车" }, { value: 13, text: "解压抵押" }, { value: 14, text: "抵押核验" } ] } filterDom = () => { let filterJson = label; let arr = filterJson.option; return ( <div ref="filterBar" className="filter-list"> {arr.map((item, index) => { if (item.value == this.state.filterSelect) { return ( <div ref={item.value} className="filter-item active" key={index} value={item.value}> {item.text} <div className="zhishi"></div> </div> ); } else { return ( <div className="filter-item" onClick={() => { this.filterBarClick(item); }} ref={item.value} key={index} value={item.value}> {item.text} </div> ); } })} </div> ); }; render(){ return( <div> ... <div className="filter-content" style={{ display: this.state.filterBarShow }}> {this.filterDom()} <div className="shadow"></div> {/* 按钮和占位 */} <div className="filte-btn-content" onClick={() => { this.filterBtnClick(); }}> <div className="filte-btn"></div> </div> </div> ... </div> ) }
scss样式表
.filter { width: 100%; // position: fixed; } .filter-content { overflow: hidden; padding-right: pxToRem(27px); position: relative; background: #fff; .filter-list { display: flex; overflow-x: auto; justify-content: space-between; height: pxToRem(90px); color: #333333; align-items: center; -webkit-overflow-scrolling: touch; font-size: pxToRem(32px); font-family:PingFangSC-Light,PingFang SC; font-weight:300; background: #fff; margin-right: pxToRem(100px); .filter-item { text-align: center; display: flex; // flex-basis: 17px; flex-shrink: 0; white-space: nowrap; padding: 0 pxToRem(25px); background: #fff; height: pxToRem(90px); align-items: center; justify-content: center; } .active{ font-size: pxToRem(36px); font-weight: 600; height: pxToRem(90px); display: flex; align-items: center; justify-content: center; position: relative; flex: 1; flex-direction: column; } .zhishi{ background: url("./../img/zhishi.png"); background-repeat: no-repeat; background-size: 100%; width: pxToRem(25px); height: pxToRem(6px); position: absolute; bottom: pxToRem(10px);; left: 50%; transform: translate(-50%, 0); z-index: 999; } } .shadow{ height: pxToRem(90px); width: pxToRem(133px); position: absolute; right: pxToRem(101px); top: 0; background:linear-gradient(270deg,rgba(255,255,255,1) 0%,rgba(255,255,255,0.14) 100%); pointer-events: none; } .filte-btn{ background: url("./../img/shaixuan.png"); background-repeat: no-repeat; background-size: 100%; width: pxToRem(40px); height: pxToRem(40px); } .filte-btn-content { height: pxToRem(90px); position: absolute; right: pxToRem(27px); top: 0; background: #fff; width: pxToRem(74px); display: flex; align-items: center; justify-content: flex-end; } }
实现
想要居中展示首先是需要找到中心点,然后在点击是计算偏移量,把对应的标签滚动到中心位置
filterBarClick = param => { const { value, text } = param; this.setState({ filterSelect: value }); let dom = this.refs; //获取点击时当前标签的DOM let valDom = dom[value]; //获取标签父元素DOM let contentDom = dom.filterBar; //计算当前标签到最左侧的宽度 let valLeft = valDom.offsetLeft; //计算当前标签本身的宽度 let valWidth = valDom.clientWidth; //当前标签中心点到最左侧的距离 let valCenter = valLeft + valWidth / 2; //可视屏幕宽度 let clientWidth = document.querySelector('body').offsetWidth; //可视屏幕中心点(减去的30是列表两边的15像素的留白) let center = (clientWidth - 30) / 2; //计算当前标签中心点和屏幕中心点的偏移量 然后滚动相应的距离 if (valCenter > center) { contentDom.scrollTo({ left: valCenter - center, behavior: 'smooth' }); } else { contentDom.scrollTo({ left: 0, behavior: 'smooth' }); } };
总结
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