vue3實(shí)現(xiàn)數(shù)字滾動特效實(shí)例詳解

更新時間：2022年09月07日 17:12:47 作者：承吾

這篇文章主要為大家介紹了vue3實(shí)現(xiàn)數(shù)字滾動特效實(shí)例詳解，有需要的朋友可以借鑒參考下，希望能夠有所幫助，祝大家多多進(jìn)步，早日升職加薪

前言

vue3不支持vue-count-to插件，無法使用vue-count-to實(shí)現(xiàn)數(shù)字動效，數(shù)字自動分割，vue-count-to主要針對vue2使用，vue3按照會報錯： TypeError: Cannot read properties of undefined (reading '_c') 的錯誤信息。這個時候我們只能自己封裝一個CountTo組件實(shí)現(xiàn)數(shù)字動效。先來看效果圖:

思路

使用Vue.component定義公共組件，使用window.requestAnimationFrame（首選，次選setTimeout）來循環(huán)數(shù)字動畫，window.cancelAnimationFrame取消數(shù)字動畫效果，封裝一個requestAnimationFrame.js公共文件，CountTo.vue組件，入口導(dǎo)出文件index.js。

文件目錄

使用示例

<CountTo
 :start="0" // 從數(shù)字多少開始
 :end="endCount" // 到數(shù)字多少結(jié)束
 :autoPlay="true" // 自動播放
 :duration="3000" // 過渡時間
 prefix="￥"   // 前綴符號
 suffix="rmb" // 后綴符號
 />

入口文件index.js

const UILib = {
  install(Vue) {
    Vue.component('CountTo', CountTo)
  }
}
export default UILib

main.js使用

import CountTo from './components/count-to/index';
app.use(CountTo)

requestAnimationFrame.js思路

先判斷是不是瀏覽器還是其他環(huán)境
如果是瀏覽器判斷瀏覽器內(nèi)核類型
如果瀏覽器不支持requestAnimationFrame，cancelAnimationFrame方法，改寫setTimeout定時器
導(dǎo)出兩個方法 requestAnimationFrame, cancelAnimationFrame

各個瀏覽器前綴：let prefixes = 'webkit moz ms o';

判斷是不是瀏覽器：let isServe = typeof window == 'undefined';

增加各個瀏覽器前綴：

let prefix;
let requestAnimationFrame;
let cancelAnimationFrame;
// 通過遍歷各瀏覽器前綴，來得到requestAnimationFrame和cancelAnimationFrame在當(dāng)前瀏覽器的實(shí)現(xiàn)形式
    for (let i = 0; i < prefixes.length; i++) {
        if (requestAnimationFrame && cancelAnimationFrame) { break }
        prefix = prefixes[i]
        requestAnimationFrame = requestAnimationFrame || window[prefix + 'RequestAnimationFrame']
        cancelAnimationFrame = cancelAnimationFrame || window[prefix + 'CancelAnimationFrame'] || window[prefix + 'CancelRequestAnimationFrame']
    }
  //不支持使用setTimeout方式替換：模擬60幀的效果
  // 如果當(dāng)前瀏覽器不支持requestAnimationFrame和cancelAnimationFrame，則會退到setTimeout
    if (!requestAnimationFrame || !cancelAnimationFrame) {
        requestAnimationFrame = function (callback) {
            const currTime = new Date().getTime()
            // 為了使setTimteout的盡可能的接近每秒60幀的效果
            const timeToCall = Math.max(0, 16 - (currTime - lastTime))
            const id = window.setTimeout(() => {
                callback(currTime + timeToCall)
            }, timeToCall)
            lastTime = currTime + timeToCall
            return id
        }
        cancelAnimationFrame = function (id) {
            window.clearTimeout(id)
        }
    }

完整代碼：

requestAnimationFrame.js

let lastTime = 0
const prefixes = 'webkit moz ms o'.split(' ') // 各瀏覽器前綴
let requestAnimationFrame
let cancelAnimationFrame
// 判斷是否是服務(wù)器環(huán)境
const isServer = typeof window === 'undefined'
if (isServer) {
    requestAnimationFrame = function () {
        return
    }
    cancelAnimationFrame = function () {
        return
    }
} else {
    requestAnimationFrame = window.requestAnimationFrame
    cancelAnimationFrame = window.cancelAnimationFrame
    let prefix
    // 通過遍歷各瀏覽器前綴，來得到requestAnimationFrame和cancelAnimationFrame在當(dāng)前瀏覽器的實(shí)現(xiàn)形式
    for (let i = 0; i < prefixes.length; i++) {
        if (requestAnimationFrame && cancelAnimationFrame) { break }
        prefix = prefixes[i]
        requestAnimationFrame = requestAnimationFrame || window[prefix + 'RequestAnimationFrame']
        cancelAnimationFrame = cancelAnimationFrame || window[prefix + 'CancelAnimationFrame'] || window[prefix + 'CancelRequestAnimationFrame']
    }
    // 如果當(dāng)前瀏覽器不支持requestAnimationFrame和cancelAnimationFrame，則會退到setTimeout
    if (!requestAnimationFrame || !cancelAnimationFrame) {
        requestAnimationFrame = function (callback) {
            const currTime = new Date().getTime()
            // 為了使setTimteout的盡可能的接近每秒60幀的效果
            const timeToCall = Math.max(0, 16 - (currTime - lastTime))
            const id = window.setTimeout(() => {
                callback(currTime + timeToCall)
            }, timeToCall)
            lastTime = currTime + timeToCall
            return id
        }
        cancelAnimationFrame = function (id) {
            window.clearTimeout(id)
        }
    }
}
export { requestAnimationFrame, cancelAnimationFrame }

CountTo.vue組件思路

首先引入requestAnimationFrame.js,使用requestAnimationFrame方法接受count函數(shù)，還需要格式化數(shù)字，進(jìn)行正則表達(dá)式轉(zhuǎn)換，返回我們想要的數(shù)據(jù)格式。

引入 import { requestAnimationFrame, cancelAnimationFrame } from './requestAnimationFrame.js'

需要接受的參數(shù)：

const props = defineProps({
  start: {
    type: Number,
    required: false,
    default: 0
  },
  end: {
    type: Number,
    required: false,
    default: 0
  },
  duration: {
    type: Number,
    required: false,
    default: 5000
  },
  autoPlay: {
    type: Boolean,
    required: false,
    default: true
  },
  decimals: {
    type: Number,
    required: false,
    default: 0,
    validator (value) {
      return value >= 0
    }
  },
  decimal: {
    type: String,
    required: false,
    default: '.'
  },
  separator: {
    type: String,
    required: false,
    default: ','
  },
  prefix: {
    type: String,
    required: false,
    default: ''
  },
  suffix: {
    type: String,
    required: false,
    default: ''
  },
  useEasing: {
    type: Boolean,
    required: false,
    default: true
  },
  easingFn: {
    type: Function,
    default(t, b, c, d) {
      return c * (-Math.pow(2, -10 * t / d) + 1) * 1024 / 1023 + b;
    }
  }
})

啟動數(shù)字動效

const startCount = () => {
  state.localStart = props.start
  state.startTime = null
  state.localDuration = props.duration
  state.paused = false
  state.rAF = requestAnimationFrame(count)
}

核心函數(shù)，對數(shù)字進(jìn)行轉(zhuǎn)動

  if (!state.startTime) state.startTime = timestamp
  state.timestamp = timestamp
  const progress = timestamp - state.startTime
  state.remaining = state.localDuration - progress
  // 是否使用速度變化曲線
  if (props.useEasing) {
    if (stopCount.value) {
      state.printVal = state.localStart - props.easingFn(progress, 0, state.localStart - props.end, state.localDuration)
    } else {
      state.printVal = props.easingFn(progress, state.localStart, props.end - state.localStart, state.localDuration)
    }
  } else {
    if (stopCount.value) {
      state.printVal = state.localStart - ((state.localStart - props.end) * (progress / state.localDuration))
    } else {
      state.printVal = state.localStart + (props.end - state.localStart) * (progress / state.localDuration)
    }
  }
  if (stopCount.value) {
    state.printVal = state.printVal < props.end ? props.end : state.printVal
  } else {
    state.printVal = state.printVal > props.end ? props.end : state.printVal
  }
  state.displayValue = formatNumber(state.printVal)
  if (progress < state.localDuration) {
    state.rAF = requestAnimationFrame(count)
  } else {
    emits('callback')
  }
}
// 格式化數(shù)據(jù)，返回想要展示的數(shù)據(jù)格式
const formatNumber = (val) => {
  val = val.toFixed(props.default)
  val += ''
  const x = val.split('.')
  let x1 = x[0]
  const x2 = x.length > 1 ? props.decimal + x[1] : ''
  const rgx = /(\d+)(\d{3})/
  if (props.separator && !isNumber(props.separator)) {
    while (rgx.test(x1)) {
      x1 = x1.replace(rgx, '$1' + props.separator + '$2')
    }
  }
  return props.prefix + x1 + x2 + props.suffix
}

取消動效

// 組件銷毀時取消動畫
onUnmounted(() => {
  cancelAnimationFrame(state.rAF)
})

完整代碼

<template>
  {{ state.displayValue }}
</template>
<script setup>  // vue3.2新的語法糖, 編寫代碼更加簡潔高效
import { onMounted, onUnmounted, reactive } from "@vue/runtime-core";
import { watch, computed } from 'vue';
import { requestAnimationFrame, cancelAnimationFrame } from './requestAnimationFrame.js'
// 定義父組件傳遞的參數(shù)
const props = defineProps({
  start: {
    type: Number,
    required: false,
    default: 0
  },
  end: {
    type: Number,
    required: false,
    default: 0
  },
  duration: {
    type: Number,
    required: false,
    default: 5000
  },
  autoPlay: {
    type: Boolean,
    required: false,
    default: true
  },
  decimals: {
    type: Number,
    required: false,
    default: 0,
    validator (value) {
      return value >= 0
    }
  },
  decimal: {
    type: String,
    required: false,
    default: '.'
  },
  separator: {
    type: String,
    required: false,
    default: ','
  },
  prefix: {
    type: String,
    required: false,
    default: ''
  },
  suffix: {
    type: String,
    required: false,
    default: ''
  },
  useEasing: {
    type: Boolean,
    required: false,
    default: true
  },
  easingFn: {
    type: Function,
    default(t, b, c, d) {
      return c * (-Math.pow(2, -10 * t / d) + 1) * 1024 / 1023 + b;
    }
  }
})
const isNumber = (val) => {
  return !isNaN(parseFloat(val))
}
// 格式化數(shù)據(jù)，返回想要展示的數(shù)據(jù)格式
const formatNumber = (val) => {
  val = val.toFixed(props.default)
  val += ''
  const x = val.split('.')
  let x1 = x[0]
  const x2 = x.length > 1 ? props.decimal + x[1] : ''
  const rgx = /(\d+)(\d{3})/
  if (props.separator && !isNumber(props.separator)) {
    while (rgx.test(x1)) {
      x1 = x1.replace(rgx, '$1' + props.separator + '$2')
    }
  }
  return props.prefix + x1 + x2 + props.suffix
}
// 相當(dāng)于vue2中的data中所定義的變量部分
const state = reactive({
  localStart: props.start,
  displayValue: formatNumber(props.start),
  printVal: null,
  paused: false,
  localDuration: props.duration,
  startTime: null,
  timestamp: null,
  remaining: null,
  rAF: null
})
// 定義一個計(jì)算屬性，當(dāng)開始數(shù)字大于結(jié)束數(shù)字時返回true
const stopCount = computed(() => {
  return props.start > props.end
})
// 定義父組件的自定義事件，子組件以觸發(fā)父組件的自定義事件
const emits = defineEmits(['onMountedcallback', 'callback'])
const startCount = () => {
  state.localStart = props.start
  state.startTime = null
  state.localDuration = props.duration
  state.paused = false
  state.rAF = requestAnimationFrame(count)
}
watch(() => props.start, () => {
  if (props.autoPlay) {
    startCount()
  }
})
watch(() => props.end, () => {
  if (props.autoPlay) {
    startCount()
  }
})
// dom掛在完成后執(zhí)行一些操作
onMounted(() => {
  if (props.autoPlay) {
    startCount()
  }
  emits('onMountedcallback')
})
// 暫停計(jì)數(shù)
const pause = () => {
  cancelAnimationFrame(state.rAF)
}
// 恢復(fù)計(jì)數(shù)
const resume = () => {
  state.startTime = null
  state.localDuration = +state.remaining
  state.localStart = +state.printVal
  requestAnimationFrame(count)
}
const pauseResume = () => {
  if (state.paused) {
    resume()
    state.paused = false
  } else {
    pause()
    state.paused = true
  }
}
const reset = () => {
  state.startTime = null
  cancelAnimationFrame(state.rAF)
  state.displayValue = formatNumber(props.start)
}
const count = (timestamp) => {
  if (!state.startTime) state.startTime = timestamp
  state.timestamp = timestamp
  const progress = timestamp - state.startTime
  state.remaining = state.localDuration - progress
  // 是否使用速度變化曲線
  if (props.useEasing) {
    if (stopCount.value) {
      state.printVal = state.localStart - props.easingFn(progress, 0, state.localStart - props.end, state.localDuration)
    } else {
      state.printVal = props.easingFn(progress, state.localStart, props.end - state.localStart, state.localDuration)
    }
  } else {
    if (stopCount.value) {
      state.printVal = state.localStart - ((state.localStart - props.end) * (progress / state.localDuration))
    } else {
      state.printVal = state.localStart + (props.end - state.localStart) * (progress / state.localDuration)
    }
  }
  if (stopCount.value) {
    state.printVal = state.printVal < props.end ? props.end : state.printVal
  } else {
    state.printVal = state.printVal > props.end ? props.end : state.printVal
  }
  state.displayValue = formatNumber(state.printVal)
  if (progress < state.localDuration) {
    state.rAF = requestAnimationFrame(count)
  } else {
    emits('callback')
  }
}
// 組件銷毀時取消動畫
onUnmounted(() => {
  cancelAnimationFrame(state.rAF)
})
</script>

總結(jié)

自己封裝數(shù)字動態(tài)效果需要注意各個瀏覽器直接的差異，手動pollyfill，暴露出去的props參數(shù)需要有默認(rèn)值，數(shù)據(jù)的格式化可以才有正則表達(dá)式的方式，組件的驅(qū)動必須是數(shù)據(jù)變化，根據(jù)數(shù)據(jù)來驅(qū)動頁面渲染，防止頁面出現(xiàn)卡頓，不要強(qiáng)行操作dom,引入的組件可以全局配置，后續(xù)組件可以服用

demo演示

后續(xù)的線上demo演示會放在 demo演示

以上就是vue3實(shí)現(xiàn)數(shù)字滾動特效實(shí)例詳解的詳細(xì)內(nèi)容，更多關(guān)于vue3數(shù)字滾動的資料請關(guān)注腳本之家其它相關(guān)文章！

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