html代码
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> #t,#tt{ border: #ccc thin solid; width: 250px; height: 60px; display: flex; justify-content: space-around; align-items: center; font-size: 20px; } .t-num{ height: 100%; overflow: hidden; /*background-color: #ccc;*/ width: 25px; line-height: 60px; text-align: center; } .t-num-s{ display: block; height: 100%; width: 100%; /*border: red thin solid;*/ } </style> </head> <body> <div> </div> <div> </div> <!--结构示例--> <!--<div>--> <!--<div><span>1</span></div>--> <!--<div><span>2</span></div>--> <!--<div><span>3</span></div>--> <!--<div><span>4</span></div>--> <!--</div>--> </body> </html> <script src="https://www.jb51.net/index.js"></script> <script> let num = 12345.5 //配置项 p:滚动熟读，height:数字容器的高度，spanclass：数字容器的classname,divClasss: span容器的class // numchange.config({p: 5}).change('t', num) let t = numchange() t.change('t', num) setInterval(() => { num = Math.random() * 100 + parseFloat(num) num = num.toFixed(2) t.change('t', num) },3000) let num1 = 12345 let t1 = numchange() t1.change('tt', num1) setInterval(() => { num1 = parseInt(Math.random() * 100) + parseInt(num1) t1.change('tt', num1) },3000) </script>
js代码
let numchange = function (){ let point = '.' // 数字容器高度 let height = 60 // 每次滚动距离/滚动速度 let p = 3 // 数字spanclass let spanClass = 't-num-s' // 数字divclass let divClass = 't-num' // let cache = {} function createDiv(id, num, len, paddingNum){ let str = '' for (let i = 0; i < len; i++) { str += `<div><span>${paddingNum === undefined?num[i]:paddingNum}</span></div>` } return str } function initZero(id, count){ document.getElementById(id).innerHTML = createDiv(id,null,count,0) } function refresh(oldNum, newNum, id){ let len = newNum.length - oldNum.length; for (let i = 0; i < len; i++) { oldNum.unshift('0') } document.getElementById(id).innerHTML = createDiv(id,oldNum,oldNum.length) } function refresh1(oldNum, newNum, id){ let len = oldNum.length - newNum.length; for (let i = 0; i < len; i++) { oldNum.shift() } document.getElementById(id).innerHTML = createDiv(id,oldNum,oldNum.length) } function scrollNum(id, num, order){ let h = num * height let e = document.getElementById(id) let t = setInterval(() => { let m = e.scrollTop; m = m + p if(m > h){ clearInterval(t) let cs = e.children for (let i = cs.length-2; i >= 0; i--) { e.removeChild(cs[i]) } return } e.scrollTop = m }, 10) } function createSpan(num){ let span = document.createElement('span') span.className = spanClass span.innerText = num return span } function appendNum(id, start, end){ let f = document.createDocumentFragment() let count = 0 if(start === end && isNaN(start)){ return 0 } if(isNaN(start) && !isNaN(end)){ for (let i = 0; i <= end; i++) { f.appendChild(createSpan(i)) count++ } document.getElementById(id).appendChild(f) return count } if(!isNaN(start) && isNaN(end)){ for (let i = start+1; i <= 9; i++) { f.appendChild(createSpan(i)) count++ } f.appendChild(createSpan('.')) count++ document.getElementById(id).appendChild(f) return count } if(start < end){ for (let i = start+1; i <= end; i++) { f.appendChild(createSpan(i)) count++ } }else if(start > end){ for (let i = start+1; i <= 9; i++) { f.appendChild(createSpan(i)) count++ } for (let i = 0; i <= end; i++) { f.appendChild(createSpan(i)) count++ } }else{ return 0 } document.getElementById(id).appendChild(f) return count } /** * @param id 容器id * @param num 展示的数字 */ function change(id, num){ console.log(num) let strArr = num.toString().split(''); let oldNum = cache[id] // 如果没有缓存，开始数字全部填充0 if(!oldNum){ initZero(id,strArr.length) oldNum = [] }else{ oldNum = cache[id].toString().split('') // 如果新数字长，原来数字左侧填充0 if(oldNum.length < strArr.length){ refresh(oldNum, strArr, id) // 如果新数字短，原来数字左侧移除 }else if(oldNum.length > strArr.length){ refresh1(oldNum, strArr, id) } } // 循环比较每个数字差异，添加需要滚动的数字列 for (let i = 0, len = strArr.length; i < len; i++) { let start = oldNum[i] !== point ? parseInt(oldNum[i]||0) : oldNum[i] let end = strArr[i] !== point ? parseInt(strArr[i]||0) : strArr[i] let count = appendNum(id+i, start, end) if(count > 0){ // 数字滚动 scrollNum(id+i, count, i+1) } } cache[id] = num } function config(param){ if(param.p){ p = param.p } if(param.height){ height = param.height } if(param.spanClass){ spanClass = param.spanClass } if(param.divClass){ divClass = param.divClass } return scroll } let scroll = { change: change, config: config } return scroll }
遗留问题：setInterval方法在切换页面后，会变快。解决方案1：用setTimeout代替setInterval。2.requestAnimFrame