这里有另一个解决方案:

<script type="text/javascript">
$.fn.is_on_screen = function(){
    var win = $(window);
    var viewport = {
        top : win.scrollTop(),
        left : win.scrollLeft()
    };
    viewport.right = viewport.left + win.width();
    viewport.bottom = viewport.top + win.height();

    var bounds = this.offset();
    bounds.right = bounds.left + this.outerWidth();
    bounds.bottom = bounds.top + this.outerHeight();

    return (!(viewport.right < bounds.left || viewport.left > bounds.right ||    viewport.bottom < bounds.top || viewport.top > bounds.bottom));
 };

if( $('.target').length > 0 ) { // if target element exists in DOM
    if( $('.target').is_on_screen() ) { // if target element is visible on screen after DOM loaded
        $('.log').html('<div class="alert alert-success">target element is visible on screen</div>'); // log info       
    } else {
        $('.log').html('<div class="alert">target element is not visible on screen</div>'); // log info
    }
}
$(window).on('scroll', function(){ // bind window scroll event
if( $('.target').length > 0 ) { // if target element exists in DOM
    if( $('.target').is_on_screen() ) { // if target element is visible on screen after DOM loaded
        $('.log').html('<div class="alert alert-success">target element is visible on screen</div>'); // log info
    } else {
        $('.log').html('<div class="alert">target element is not visible on screen</div>'); // log info
    }
}
});
</script>

在JSFiddle中可以看到

WebResourcesDepot在前段时间使用jQuery编写了一个滚动加载脚本。你可以在这里查看他们的现场演示。它们功能的关键在于:

$(window).scroll(function(){
  if  ($(window).scrollTop() == $(document).height() - $(window).height()){
    lastAddedLiveFunc();
  }
});

function lastAddedLiveFunc() { 
  $('div#lastPostsLoader').html('<img src="images/bigLoader.gif">');
  $.post("default.asp?action=getLastPosts&lastPostID="+$(".wrdLatest:last").attr("id"),
    function(data){
        if (data != "") {
          $(".wrdLatest:last").after(data);         
        }
      $('div#lastPostsLoader').empty();
    });
};

当你滚动时，你可以使用jquery插件“onScreen”来检查元素是否在当前视口中。 当选择器出现在屏幕上时，插件将选择器的":onScreen"设置为true。 这是插件的链接，你可以把它包含在你的项目中。 “http://benpickles.github.io/onScreen/jquery.onscreen.min.js”

你可以试试下面这个适合我的例子。

$(document).scroll(function() {
    if($("#div2").is(':onScreen')) {
        console.log("Element appeared on Screen");
        //do all your stuffs here when element is visible.
    }
    else {
        console.log("Element not on Screen");
        //do all your stuffs here when element is not visible.
    }
});

HTML代码:

<div id="div1" style="width: 400px; height: 1000px; padding-top: 20px; position: relative; top: 45px"></div> <br>
<hr /> <br>
<div id="div2" style="width: 400px; height: 200px"></div>

CSS:

#div1 {
    background-color: red;
}
#div2 {
    background-color: green;
}

唯一适用于我的解决方案是(当$("#elementToCheck")可见时返回true):

$ (document) .scrollTop () + window.innerHeight + $ (" # elementToCheck ") .height () > $ (" # elementToCheck ") .offset直()上

制作了一个简单的插件，用于检测元素在可滚动容器中是否可见

    $.fn.isVisible = function(){

      var win;
      if(!arguments[0])
      {
        console.error('Specify a target;');
        return false;
      }
      else
      {
        win = $(arguments[0]);
      }
      var viewport = {};
      var bounds = this.offset();
      bounds.right = bounds.left + this.outerWidth();
      bounds.bottom = bounds.top + this.outerHeight();
      viewport.bottom = win.height() + win.offset().top;
      return (!( bounds.top > viewport.bottom) && (win.offset().top < bounds.bottom));
    };

像这样调用$('elem_to_check').isVisible('scrollable_container');

希望能有所帮助。

这应该可以达到目的:

function isScrolledIntoView(elem)
{
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

简单实用函数 这将允许您调用一个实用函数，该函数接受您正在寻找的元素，以及您希望元素完全或部分地显示在视图中。

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();

使用

var isElementInView = Utils.isElementInView($('#flyout-left-container'), false);

if (isElementInView) {
    console.log('in view');
} else {
    console.log('out of view');
}