$(window)

  .on("scrollstart", function() {

    // Paint the world yellow when scrolling starts.

    $(document.body).css({background: "yellow"});

  })

  .on("scrollstop", function() {

    // Paint it all green when scrolling stops.

    $(document.body).css({background: "green"});

  });

https://github.com/ssorallen/jquery-scrollstop

开始滚动和停止滚动的时候 会发出事件