CountUp.js实现数字滚动增值效果

// target = id of html element or var of previously selected html element where counting occurs
// startVal = the value you want to begin at
// endVal = the value you want to arrive at
// decimals = number of decimal places, default 0
// duration = duration of animation in seconds, default 2
// options = optional object of options (see below)
 
var CountUp = function (target, startVal, endVal, decimals, duration, options) {
 var self = this
 self.version = function () { return '1.9.3' }
 
 // default options
 self.options = {
 useEasing: true, // toggle easing
 useGrouping: true, // 1,000,000 vs 1000000
 separator: ',', // character to use as a separator
 decimal: '.', // character to use as a decimal
 easingFn: easeOutExpo, // optional custom easing function, default is Robert Penner's easeOutExpo
 formattingFn: formatNumber, // optional custom formatting function, default is formatNumber above
 prefix: '', // optional text before the result
 suffix: '', // optional text after the result
 numerals: [] // optionally pass an array of custom numerals for 0-9
 }
 
 // extend default options with passed options object
 if (options && typeof options === 'object') {
 for (var key in self.options) {
 if (options.hasOwnProperty(key) && options[key] !== null) {
 self.options[key] = options[key]
 }
 }
 }
 
 if (self.options.separator === '') {
 self.options.useGrouping = false
 } else {
 // ensure the separator is a string (formatNumber assumes this)
 self.options.separator = '' + self.options.separator
 }
 
 // make sure requestAnimationFrame and cancelAnimationFrame are defined
 // polyfill for browsers without native support
 // by Opera engineer Erik Möller
 var lastTime = 0
 var vendors = ['webkit', 'moz', 'ms', 'o']
 for (var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
 window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame']
 window.cancelAnimationFrame = window[vendors[x] + 'CancelAnimationFrame'] || window[vendors[x] + 'CancelRequestAnimationFrame']
 }
 if (!window.requestAnimationFrame) {
 window.requestAnimationFrame = function (callback, element) {
 var currTime = new Date().getTime()
 var timeToCall = Math.max(0, 16 - (currTime - lastTime))
 var tesult = currTime + timeToCall
 var id = window.setTimeout(function () { callback(tesult) }, timeToCall)
 lastTime = currTime + timeToCall
 return id
 }
 }
 if (!window.cancelAnimationFrame) {
 window.cancelAnimationFrame = function (id) {
 clearTimeout(id)
 }
 }
 
 function formatNumber (num) {
 var neg = (num < 0)
 var x, x1, x2, x3, i, len
 num = Math.abs(num).toFixed(self.decimals)
 num += ''
 x = num.split('.')
 x1 = x[0]
 x2 = x.length > 1 ? self.options.decimal + x[1] : ''
 if (self.options.useGrouping) {
 x3 = ''
 for (i = 0, len = x1.length; i < len; ++i) {
 if (i !== 0 && ((i % 3) === 0)) {
 x3 = self.options.separator + x3
 }
 x3 = x1[len - i - 1] + x3
 }
 x1 = x3
 }
 // optional numeral substitution
 if (self.options.numerals.length) {
 x1 = x1.replace(/[0-9]/g, function (w) {
 return self.options.numerals[+w]
 })
 x2 = x2.replace(/[0-9]/g, function (w) {
 return self.options.numerals[+w]
 })
 }
 return (neg ? '-' : '') + self.options.prefix + x1 + x2 + self.options.suffix
 }
 // Robert Penner's easeOutExpo
 function easeOutExpo (t, b, c, d) {
 return c * (-Math.pow(2, -10 * t / d) + 1) * 1024 / 1023 + b
 }
 function ensureNumber (n) {
 return (typeof n === 'number' && !isNaN(n))
 }
 
 self.initialize = function () {
 if (self.initialized) return true
 
 self.error = ''
 self.d = (typeof target === 'string') ? document.getElementById(target) : target
 if (!self.d) {
 self.error = '[CountUp] target is null or undefined'
 return false
 }
 self.startVal = Number(startVal)
 self.endVal = Number(endVal)
 // error checks
 if (ensureNumber(self.startVal) && ensureNumber(self.endVal)) {
 self.decimals = Math.max(0, decimals || 0)
 self.dec = Math.pow(10, self.decimals)
 self.duration = Number(duration) * 1000 || 2000
 self.countDown = (self.startVal > self.endVal)
 self.frameVal = self.startVal
 self.initialized = true
 return true
 } else {
 self.error = '[CountUp] startVal (' + startVal + ') or endVal (' + endVal + ') is not a number'
 return false
 }
 }
 
 // Print value to target
 self.printValue = function (value) {
 var result = self.options.formattingFn(value)
 
 if (self.d.tagName === 'INPUT') {
 this.d.value = result
 } else if (self.d.tagName === 'text' || self.d.tagName === 'tspan') {
 this.d.textContent = result
 } else {
 this.d.innerHTML = result
 }
 }
 
 self.count = function (timestamp) {
 if (!self.startTime) { self.startTime = timestamp }
 
 self.timestamp = timestamp
 var progress = timestamp - self.startTime
 self.remaining = self.duration - progress
 
 // to ease or not to ease
 if (self.options.useEasing) {
 if (self.countDown) {
 self.frameVal = self.startVal - self.options.easingFn(progress, 0, self.startVal - self.endVal, self.duration)
 } else {
 self.frameVal = self.options.easingFn(progress, self.startVal, self.endVal - self.startVal, self.duration)
 }
 } else {
 if (self.countDown) {
 self.frameVal = self.startVal - ((self.startVal - self.endVal) * (progress / self.duration))
 } else {
 self.frameVal = self.startVal + (self.endVal - self.startVal) * (progress / self.duration)
 }
 }
 
 // don't go past endVal since progress can exceed duration in the last frame
 if (self.countDown) {
 self.frameVal = (self.frameVal < self.endVal) ? self.endVal : self.frameVal
 } else {
 self.frameVal = (self.frameVal > self.endVal) ? self.endVal : self.frameVal
 }
 
 // decimal
 self.frameVal = Math.round(self.frameVal * self.dec) / self.dec
 
 // format and print value
 self.printValue(self.frameVal)
 
 // whether to continue
 if (progress < self.duration) {
 self.rAF = requestAnimationFrame(self.count)
 } else {
 if (self.callback) self.callback()
 }
 }
 // start your animation
 self.start = function (callback) {
 if (!self.initialize()) return
 self.callback = callback
 self.rAF = requestAnimationFrame(self.count)
 }
 // toggles pause/resume animation
 self.pauseResume = function () {
 if (!self.paused) {
 self.paused = true
 cancelAnimationFrame(self.rAF)
 } else {
 self.paused = false
 delete self.startTime
 self.duration = self.remaining
 self.startVal = self.frameVal
 requestAnimationFrame(self.count)
 }
 }
 // reset to startVal so animation can be run again
 self.reset = function () {
 self.paused = false
 delete self.startTime
 self.initialized = false
 if (self.initialize()) {
 cancelAnimationFrame(self.rAF)
 self.printValue(self.startVal)
 }
 }
 // pass a new endVal and start animation
 self.update = function (newEndVal) {
 if (!self.initialize()) return
 newEndVal = Number(newEndVal)
 if (!ensureNumber(newEndVal)) {
 self.error = '[CountUp] update() - new endVal is not a number: ' + newEndVal
 return
 }
 self.error = ''
 if (newEndVal === self.frameVal) return
 cancelAnimationFrame(self.rAF)
 self.paused = false
 delete self.startTime
 self.startVal = self.frameVal
 self.endVal = newEndVal
 self.countDown = (self.startVal > self.endVal)
 self.rAF = requestAnimationFrame(self.count)
 }
 
 // format startVal on initialization
 if (self.initialize()) self.printValue(self.startVal)
}
module.exports = CountUp

var options = {
 useEasing: true, // 使用缓和效果
 useGrouping: true, // 使用分组效果
 separator: ',', // 分离器，数据够三位，例如100,000
 decimal: '.', // 小数点分割，例如：10.00
 prefix: '', // 第一位默认数字，例如：¥
 suffix: '' // 最后一位默认数字，例如：元，美元
 }
 // new CountUp(target, startVal, endVal, decimals, duration, options)
 // target = 目标元素的 ID
 // startVal = 开始值
 // endVal = 结束值
 // decimals = 小数位数 默认值是0
 // duration = 动画延迟秒数，默认值是2；
 // options = optional object of options (see below)
 
 var demo = new CountUp('extractionMoney', 0, data.balanceAmount, 2, 0.5, options)
 if (!demo.error) {
 demo.start()
 } else {
 console.error(demo.error)
 }