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countUp.js實(shí)現(xiàn)數(shù)字滾動(dòng)效果

更新時(shí)間：2019年10月18日 13:44:47 作者：ajuan

這篇文章主要為大家詳細(xì)介紹了countUp.js實(shí)現(xiàn)數(shù)字滾動(dòng)效果,文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了countUp.js數(shù)字滾動(dòng)效果展示的具體代碼，供大家參考，具體內(nèi)容如下

1. 概述

1.1 說明

在項(xiàng)目過程中，有時(shí)候需要?jiǎng)討B(tài)的去展示一些數(shù)據(jù)的加載狀態(tài)，如一個(gè)數(shù)字為10000，需要5秒時(shí)間滾動(dòng)加載完成。此時(shí)使用countup.js就能夠很方便的處理此類功能問題。

1.2 countup.js

countup.js是一個(gè)無依賴性、輕量級(jí)的javascript類，可用于快速創(chuàng)建動(dòng)畫，以更有趣的方式顯示數(shù)字/數(shù)據(jù)。詳見countup.js

1.3 countup.js使用

npm install countup 進(jìn)行安裝依賴

import CountUp from "countup" 在頁面中引入

new CountUp(target, startVal, endVal, decimals, duration, options)

參數(shù)：

target: 目標(biāo)元素的id *必填
startVal：開始的值(從哪個(gè)值開始) *必填
endVal：結(jié)束的值(滾動(dòng)到哪個(gè)值結(jié)束) *必填
decimals：小數(shù)位數(shù)，默認(rèn)值為0 *可選
duration：動(dòng)畫持續(xù)時(shí)間，單位為秒，默認(rèn)值為2 *可選
options：選項(xiàng)的可選對(duì)象 *可選

useEasing:true --是否使用緩動(dòng)動(dòng)畫，默認(rèn)為緩動(dòng)，可設(shè)置為false讓其勻速

useGrouping:true --對(duì)數(shù)字進(jìn)行分組，如12345，按三位一組變?yōu)轭愃?2,345這樣的

separator: ',' --分組時(shí)使用的分隔符默認(rèn)是逗號(hào)

decimal: '.' --小數(shù)點(diǎn)

prefix: '' --添加前綴如12345，變?yōu)椋?2345

suffix: '' --添加后綴如12345 通過添加后綴變?yōu)?2345$，12345元之類的

方法：

暫停/恢復(fù)      pauseResume
重置動(dòng)畫       reset
更新值           update(newVal)

2. 代碼

2.1 源代碼

var CountUp = function(target, startVal, endVal, decimals, duration, options) {
 var self = this;
 self.version = function() {
 return "1.9.2"
 };
 self.options = {
 useEasing: true,
 useGrouping: true,
 separator: ",",
 decimal: ".",
 easingFn: easeOutExpo,
 formattingFn: formatNumber,
 prefix: "",
 suffix: "",
 numerals: []
 };
 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 {
 self.options.separator = "" + self.options.separator
 }
 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 id = window.setTimeout(function() {
  callback(currTime + timeToCall)
  },
  timeToCall);
  lastTime = currTime + timeToCall;
  return id
 }
 }
 if (!window.cancelAnimationFrame) {
 window.cancelAnimationFrame = function(id) {
  clearTimeout(id)
 }
 }
 function formatNumber(num) {
 num = num.toFixed(self.decimals);
 num += "";
 var x, x1, x2, x3, i, l;
 x = num.split(".");
 x1 = x[0];
 x2 = x.length > 1 ? self.options.decimal + x[1] : "";
 if (self.options.useGrouping) {
  x3 = "";
  for (i = 0, l = x1.length; i < l; ++i) {
  if (i !== 0 && ((i % 3) === 0)) {
   x3 = self.options.separator + x3
  }
  x3 = x1[l - i - 1] + x3
  }
  x1 = x3
 }
 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 self.options.prefix + x1 + x2 + self.options.suffix
 }
 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);
 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
 }
 };
 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;
 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)
  }
 }
 if (self.countDown) {
  self.frameVal = (self.frameVal < self.endVal) ? self.endVal: self.frameVal
 } else {
  self.frameVal = (self.frameVal > self.endVal) ? self.endVal: self.frameVal
 }
 self.frameVal = Math.round(self.frameVal * self.dec) / self.dec;
 self.printValue(self.frameVal);
 if (progress < self.duration) {
  self.rAF = requestAnimationFrame(self.count)
 } else {
  if (self.callback) {
  self.callback()
  }
 }
 };
 self.start = function(callback) {
 if (!self.initialize()) {
  return
 }
 self.callback = callback;
 self.rAF = requestAnimationFrame(self.count)
 };
 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)
 }
 };
 self.reset = function() {
 self.paused = false;
 delete self.startTime;
 self.initialized = false;
 if (self.initialize()) {
  cancelAnimationFrame(self.rAF);
  self.printValue(self.startVal)
 }
 };
 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)
 };
 if (self.initialize()) {
 self.printValue(self.startVal)
 }
};

2.1 代碼示例

<!-- 數(shù)字滾動(dòng) -->
<template>
 <div id="numScroll" style="width: 200px;height: 200px;font-size: 30px;font-weight: bold;"></div>
</template>

<script>
 import CountUp from "countup"
 export default {
 name: "numberScroll.vue",
 mounted() {
 this.numberScroll()
 },
 methods: {
 numberScroll() {
 let count = new CountUp("numScroll", 0, 56565, 0, 5, {duration: 5, useEasing: false})
 if (!count.error) {
  count.start()
 } else {
  console.log(count.error)
 }
 }
 }
 }
</script>

以上就是本文的全部內(nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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