jQuery-当用户从当前位置向上滚动100px时运行一个函数

Question

I am trying to run a function once the user has scrolled up 100px and another function when they scroll down (any number of pixels) from there current location. So if the user scrolls half way down a page and then starts to scroll up i need a function to run once they have scrolled up 100px from the current stored scrollTop value.

If the user was 700px down the page and they started to scroll up I need a function to run when they hit 600px. This should be dynamic from where ever the user is down the page.

As a starting point i have:

var lastScrollTop = 0;

$(window).scroll(function(event){
    var st = $(this).scrollTop();

    if (st > lastScrollTop){
        // Scrolling down
    } else {
        // Scrolling up
    }
    lastScrollTop = st;
});

Thanks

Answer 1

jsFiddle(http:/jsfiddle.net/nick_craver/gWD66/1/)

Try this link. May be its very helpful for you

use this Code

 <script type="text/javascript">
var position = $(window).scrollTop();
$(window).scroll(function() {
    var scroll = $(window).scrollTop();
    if(scroll > position) {
      moveCarDownward(scroll);  // $('#status').html('going down!');
    } else {
       moveCarUpward(scroll);  //$('#status').html('going up!');
    }
    position = scroll;
});

one another link which one in javascript link