使用纯 Javascript 滚动到可滚动 DIV 内的元素

Question

I have a div that has overflow: scroll and I have some elements inside the DIV that are hidden. On click of a button on the page, I want to make the DIV scroll to a particular element inside the DIV.

How do I achieve this?

Answer 1

You need to read the offsetTop property of the div you need to scroll to and then set that offset to the scrollTop property of the container div . Bind this function the event you want to :

 function scrollToElementD(){ var topPos = document.getElementById('inner-element').offsetTop; document.getElementById('container').scrollTop = topPos-10; }

 div { height: 200px; width: 100px; border: 1px solid black; overflow: auto; } p { height: 80px; background: blue; } #inner-element { background: red; }

 <div id="container"><p>A</p><p>B</p><p>C</p><p id="inner-element">D</p><p>E</p><p>F</p></div> <button onclick="scrollToElementD()">SCROLL TO D</button>

function scrollToElementD(){
  var topPos = document.getElementById('inner-element').offsetTop;
  document.getElementById('container').scrollTop = topPos-10;
}

Fiddle : http://jsfiddle.net/p3kar5bb/322/ (courtesy @rofrischmann)

Answer 2

Just improved it by setting a smooth auto scrolling inside a list contained in a div

https://codepen.io/rebosante/pen/eENYBv

var topPos = elem.offsetTop

document.getElementById('mybutton').onclick = function () {
   console.log('click')
  scrollTo(document.getElementById('container'), topPos-10, 600);   
}

function scrollTo(element, to, duration) {
    var start = element.scrollTop,
        change = to - start,
        currentTime = 0,
        increment = 20;

    var animateScroll = function(){        
        currentTime += increment;
        var val = Math.easeInOutQuad(currentTime, start, change, duration);
        element.scrollTop = val;
        if(currentTime < duration) {
            setTimeout(animateScroll, increment);
        }
    };
    animateScroll();
}

//t = current time
//b = start value
//c = change in value
//d = duration
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;
};

I guess it may help someone :)

Answer 3

Here's a simple pure JavaScript solution that works for a target Number (value for scrollTop ), target DOM element, or some special String cases:

/**
 * target - target to scroll to (DOM element, scrollTop Number, 'top', or 'bottom'
 * containerEl - DOM element for the container with scrollbars
 */
var scrollToTarget = function(target, containerEl) {
    // Moved up here for readability:
    var isElement = target && target.nodeType === 1,
        isNumber = Object.prototype.toString.call(target) === '[object Number]';

    if (isElement) {
        containerEl.scrollTop = target.offsetTop;
    } else if (isNumber) {
        containerEl.scrollTop = target;
    } else if (target === 'bottom') {
        containerEl.scrollTop = containerEl.scrollHeight - containerEl.offsetHeight;
    } else if (target === 'top') {
        containerEl.scrollTop = 0;
    }
};

And here are some examples of usage:

// Scroll to the top
var scrollableDiv = document.getElementById('scrollable_div');
scrollToTarget('top', scrollableDiv);

or

// Scroll to 200px from the top
var scrollableDiv = document.getElementById('scrollable_div');
scrollToTarget(200, scrollableDiv);

or

// Scroll to targetElement
var scrollableDiv = document.getElementById('scrollable_div');
var targetElement= document.getElementById('target_element');
scrollToTarget(targetElement, scrollableDiv);