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关于javascript:scrollTo滚动效果

Math.easeInOutQuad = function (t, b, c, d) {
t /= d / 2
if (t < 1) {

return c / 2 * t * t + b

}
t–
return -c / 2 (t (t – 2) – 1) + b
}

// requestAnimationFrame for Smart Animating http://goo.gl/sx5sts
var requestAnimFrame = (function () {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (callback) {window.setTimeout(callback, 1000 / 60) }
})()

/**

  • Because it’s so fucking difficult to detect the scrolling element, just move them all
  • @param {number} amount

*/
function move(amount, domTarget) {
if (domTarget && document.querySelector(domTarget)) {

document.querySelector(domTarget).scrollTop = amount

} else if (document.querySelector(‘.base’)) {

document.querySelector('.base').scrollTop = amount

}
document.documentElement.scrollTop = amount
document.body.parentNode.scrollTop = amount
document.body.scrollTop = amount
}

function position(domTarget) {
if (domTarget && document.querySelector(domTarget)) {

return document.querySelector(domTarget).scrollTop || document.documentElement.scrollTop || document.body.parentNode.scrollTop || document.body.scrollTop

}
return document.querySelector(‘.base’) && document.querySelector(‘.base’).scrollTop || document.documentElement.scrollTop || document.body.parentNode.scrollTop || document.body.scrollTop
}

/**

  • @param {number} to
  • @param {number} duration
  • @param {Function} callback

*/
export function scrollTo(to, duration, callback, domTarget) {
const start = position(domTarget)
const change = to – start
const increment = 20
let currentTime = 0
duration = (typeof (duration) === ‘undefined’) ? 500 : duration
var animateScroll = function () {

// increment the time
currentTime += increment
// find the value with the quadratic in-out easing function
var val = Math.easeInOutQuad(currentTime, start, change, duration)
// move the document.body
move(val, domTarget)
// do the animation unless its over
if (currentTime < duration) {requestAnimFrame(animateScroll)
} else {if (callback && typeof (callback) === 'function') {
    // the animation is done so lets callback
    callback()}
}

}
animateScroll()
}

// 代码中应用
// import {scrollTo} from “Tools/scroll-to”;
// scrollTo(0, 1600, ”, ‘.target’);

退出移动版