在JavaScript中滚动底部

时间:2019-03-21 12:49:16

标签: javascript

我在JavaScript中有一个可运行的底部函数,用于检测用户是否在底部滚动。但是,当用户的分辨率(例如Windows缩放比例)很奇怪或缩放时,就会出现问题。该功能不再起作用,无法检测到底部。

这就是我所做的:

    const bottom = e.target.scrollHeight - e.target.scrollTop === e.target.clientHeight;

    if (bottom) {
        this.props.getNewValues();
    }

有办法避免这种情况吗?即使您不缩放,这对于在电视或类似设备上显示网站的人也不起作用(就像我的一个朋友一样)

谢谢

编辑:我将其应用于精确的元素上,我重复说我的解决方案除了通过缩放外,其余都是有效的。取消缩放会提供浮动值,使响应无法真正准确地显示(根据缩放比例,其差异为1到50像素)

1 个答案:

答案 0 :(得分:1)

我使用了此功能(不能像别人写的那样获得荣誉-很抱歉,没有信用-很久以前)。也许您可以使它适应您的用例:

(function($) {

    //CHECK SCROLLED INTO VIEW UTIL
    function Utils() {

    }

    Utils.prototype = {
        constructor: Utils,
        isElementInView: function (element, fullyInView) {
            var pageTop = $(window).scrollTop();
            var pageBottom = pageTop + $(window).height();
            var elementTop = $(element).offset().top;
            var elementBottom = elementTop + $(element).height();

            if (fullyInView === true) {
                return ((pageTop < elementTop) && (pageBottom > elementBottom));
            } else {
                return ((elementTop <= pageBottom) && (elementBottom >= pageTop));
            }
        }
    };

    var Utils = new Utils();
    //END CHECK SCROLLED INTO VIEW UTIL

    //USING THE ELEMENT IN VIEW UTIL
    //this function tells what to do do when the element is or isnt in view.
    //var inView = Utils.isElementInView(el, false); Where FALSE means the element doesnt need to be completely in view / TRUE would mean the element needs to be completely in view
    function IsEInView(el) {

        var inView = Utils.isElementInView(el, false);

        if(inView) {

            //console.log('in view');

        } else {
            //console.log('not in view');
        }

    };

    //Check to make sure the element you want to be sure is visible is present on the page
    var variableOfYourElement = $('#variableOfYourElement');

    //if it is on this page run the function that checks to see if it is partially or fully in view
    if( variableOfYourElement.length ) {

        //run function on page load
        IsEInView(variableOfYourElement);

        //run function if the element scrolls into view
        $(window).scroll(function(){

            IsEInView(variableOfYourElement);

        });

    }
    //END USING THE ELEMENT IN VIEW UTIL

})(jQuery);