事件 – jQuery能否确定当前用户浏览器视图中的哪些div？

$(document).scroll(function() {
  var $this = $(this),scrollTop = $this.scrollTop(),// find the section next to the current scroll top
      sections = $(this).find('section'),topSection = null,minDist = Infinity;

  sections.each(function() {
    // calculate top and bottom offset of the section
    var top = $(this).offset().top,bottom = top + $(this).innerHeight(),// only use the minimum distance to the scroll top
        relativeDistance = Math.min(
          Math.abs(top - scrollTop),Math.abs(bottom - scrollTop)
        );
    // in case the distance is smaller than
    // the prevIoUs one's replace it
    if (relativeDistance < minDist) {
      minDist = relativeDistance;
      topSection = this;
    }
  });

  // flip the 'top' class from current to Now next one
  $('section.top').removeClass('top');
  $(topSection).addClass('top');    
});

你可以在Play Webframework’s Homepage看到一个非常好的例子

如果这不是您想要的,您可以观察任何元素的完整偏移或位置,并使用$(window).innerWidth()或$(window).innerHeight()将其与当前视口进行比较.

updatE
添加了jsbin以查看它的实际效果.请享用