我正在寻找一个简单的,跨浏览器“滚动到顶部”的动画,我可以应用到一个链接。我不想需要一个JS库,如jQuery/Moo等。

// jQuery Equivilant to convert to pure JS...
$('html, body').animate({scrollTop:0}, 400);

对于那些在跳进图书馆之前应该100%学习JS的人来说,我是一个完美的例子。:(


当前回答

没有JQuery代码,希望这将帮助你。

function TopscrollTo() {
if(window.scrollY!=0)
{
    setTimeout(function() {
       window.scrollTo(0,window.scrollY-30);
        TopscrollTo();
    }, 100);
   }
}

在按钮单击事件或任何其他你想要的元素/事件上调用这个TopscrollTo()函数。

其他回答

我修改了TimWolla的答案,使用二次输入-输出缓和(更流畅一点:)。下面是一个正在运行的示例:在jsFiddle上。这里提供了缓动函数:Robert Penner的缓动函数

document.getElementsByTagName('button')[0].onclick = function () {
    scrollTo(document.body, 0, 1250);   
}

function scrollTo(element, to, duration) {
    var start = element.scrollTop,
        change = to - start,
        increment = 20;

    var animateScroll = function(elapsedTime) {        
        elapsedTime += increment;
        var position = easeInOut(elapsedTime, start, change, duration);                        
        element.scrollTop = position; 
        if (elapsedTime < duration) {
            setTimeout(function() {
                animateScroll(elapsedTime);
            }, increment);
        }
    };

    animateScroll(0);
}

function easeInOut(currentTime, start, change, duration) {
    currentTime /= duration / 2;
    if (currentTime < 1) {
        return change / 2 * currentTime * currentTime + start;
    }
    currentTime -= 1;
    return -change / 2 * (currentTime * (currentTime - 2) - 1) + start;
}

只做了这个javascript解决方案下面。

简单的用法:

EPPZScrollTo.scrollVerticalToElementById('wrapper', 0);

引擎对象(你可以摆弄过滤器,fps值):

/**
 *
 * Created by Borbás Geri on 12/17/13
 * Copyright (c) 2013 eppz! development, LLC.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */


var EPPZScrollTo =
{
    /**
     * Helpers.
     */
    documentVerticalScrollPosition: function()
    {
        if (self.pageYOffset) return self.pageYOffset; // Firefox, Chrome, Opera, Safari.
        if (document.documentElement && document.documentElement.scrollTop) return document.documentElement.scrollTop; // Internet Explorer 6 (standards mode).
        if (document.body.scrollTop) return document.body.scrollTop; // Internet Explorer 6, 7 and 8.
        return 0; // None of the above.
    },

    viewportHeight: function()
    { return (document.compatMode === "CSS1Compat") ? document.documentElement.clientHeight : document.body.clientHeight; },

    documentHeight: function()
    { return (document.height !== undefined) ? document.height : document.body.offsetHeight; },

    documentMaximumScrollPosition: function()
    { return this.documentHeight() - this.viewportHeight(); },

    elementVerticalClientPositionById: function(id)
    {
        var element = document.getElementById(id);
        var rectangle = element.getBoundingClientRect();
        return rectangle.top;
    },

    /**
     * Animation tick.
     */
    scrollVerticalTickToPosition: function(currentPosition, targetPosition)
    {
        var filter = 0.2;
        var fps = 60;
        var difference = parseFloat(targetPosition) - parseFloat(currentPosition);

        // Snap, then stop if arrived.
        var arrived = (Math.abs(difference) <= 0.5);
        if (arrived)
        {
            // Apply target.
            scrollTo(0.0, targetPosition);
            return;
        }

        // Filtered position.
        currentPosition = (parseFloat(currentPosition) * (1.0 - filter)) + (parseFloat(targetPosition) * filter);

        // Apply target.
        scrollTo(0.0, Math.round(currentPosition));

        // Schedule next tick.
        setTimeout("EPPZScrollTo.scrollVerticalTickToPosition("+currentPosition+", "+targetPosition+")", (1000 / fps));
    },

    /**
     * For public use.
     *
     * @param id The id of the element to scroll to.
     * @param padding Top padding to apply above element.
     */
    scrollVerticalToElementById: function(id, padding)
    {
        var element = document.getElementById(id);
        if (element == null)
        {
            console.warn('Cannot find element with id \''+id+'\'.');
            return;
        }

        var targetPosition = this.documentVerticalScrollPosition() + this.elementVerticalClientPositionById(id) - padding;
        var currentPosition = this.documentVerticalScrollPosition();

        // Clamp.
        var maximumScrollPosition = this.documentMaximumScrollPosition();
        if (targetPosition > maximumScrollPosition) targetPosition = maximumScrollPosition;

        // Start animation.
        this.scrollVerticalTickToPosition(currentPosition, targetPosition);
    }
};

我看到上面大多数/所有的帖子都是用javascript搜索按钮的。这是有效的,只要你只有一个按钮。我建议在按钮内定义一个“onclick”元素。然后,“onclick”将调用该函数,使其滚动。

如果你这样做,你可以使用多个按钮,只要按钮看起来像这样:

<button onclick="scrollTo(document.body, 0, 1250)">To the top</button>

我修改了@TimWolla的代码,添加了更多的选项和一些移动功能。 另外,增加了对document.body.scrollTop和document.documentElement.scrollTop的跨浏览器支持

// scroll to top
scrollTo(0, 1000);

// Element to move, time in ms to animate
function scrollTo(element, duration) {
    var e = document.documentElement;
    if(e.scrollTop===0){
        var t = e.scrollTop;
        ++e.scrollTop;
        e = t+1===e.scrollTop--?e:document.body;
    }
    scrollToC(e, e.scrollTop, element, duration);
}

// Element to move, element or px from, element or px to, time in ms to animate
function scrollToC(element, from, to, duration) {
    if (duration <= 0) return;
    if(typeof from === "object")from=from.offsetTop;
    if(typeof to === "object")to=to.offsetTop;

    scrollToX(element, from, to, 0, 1/duration, 20, easeOutCuaic);
}

function scrollToX(element, xFrom, xTo, t01, speed, step, motion) {
    if (t01 < 0 || t01 > 1 || speed<= 0) {
        element.scrollTop = xTo;
        return;
    }
    element.scrollTop = xFrom - (xFrom - xTo) * motion(t01);
    t01 += speed * step;

    setTimeout(function() {
        scrollToX(element, xFrom, xTo, t01, speed, step, motion);
    }, step);
}
function easeOutCuaic(t){
    t--;
    return t*t*t+1;
}

http://jsfiddle.net/forestrf/tPQSv/

简化版: http://jsfiddle.net/forestrf/tPQSv/139/

// c = element to scroll to or top position in pixels
// e = duration of the scroll in ms, time scrolling
// d = (optative) ease function. Default easeOutCuaic
function scrollTo(c,e,d){d||(d=easeOutCuaic);var a=document.documentElement;if(0===a.scrollTop){var b=a.scrollTop;++a.scrollTop;a=b+1===a.scrollTop--?a:document.body}b=a.scrollTop;0>=e||("object"===typeof b&&(b=b.offsetTop),"object"===typeof c&&(c=c.offsetTop),function(a,b,c,f,d,e,h){function g(){0>f||1<f||0>=d?a.scrollTop=c:(a.scrollTop=b-(b-c)*h(f),f+=d*e,setTimeout(g,e))}g()}(a,b,c,0,1/e,20,d))};
function easeOutCuaic(t){
    t--;
    return t*t*t+1;
}

线性滚动动画到底部。纯JS,没有JQuery。也许我的解决方案会对某人有所帮助。

let action_count = 8;
let speed_ms = 15;
let objDiv = document.getElementsByClassName('js_y5_area3').item(0);

let scroll_height = objDiv.scrollHeight;
let window_height = objDiv.offsetHeight;

let scroll_top = objDiv.scrollTop;
let need_scroll_top = scroll_height - window_height;

if (scroll_top < need_scroll_top)
{
    let step = Math.ceil((need_scroll_top - scroll_top) / action_count);

    let scrollInterval = setInterval(function()
    {
        scroll_top += step;
        objDiv.scrollTop = scroll_top;

        if (scroll_top >= need_scroll_top)
        {
            clearInterval(scrollInterval);
        }

    }, speed_ms);
}

你可以改变变量action_count, speed_ms来配置滚动动画。