jQuery的动画滚动事件？

Question

I have this code

$(document).scroll(function() {
    var $window = $(window);
    var position = $window.scrollTop();

    if(position <= 2950){
        $(".lion_head").animate({right: "-100px"}, 2000);
    };
});

So if I scroll from 2950px the .lion_head will move -100px from right, What I want is when I scroll down, or scroll up, or when my scroll bar is not on 2950px , The position of my .lion_head moves to its original position?

thanks.

Answer 1

Try wrapping your code inside $(window).on('scroll', function(e){ ... }); .

In side the event function, do your animation logic.

$(window).on('scroll', function(e){
    var position = $(window).scrollTop();

    if(position <= 2950){
       $(".lion_head").animate({right: "-100px"}, 2000);
    }
    else{
       $(".lion_head").animate({right: "0"}, 2000);
    }
});

See jQuery.scroll for more details.

Answer 2

Use pure javascript

var lionHead = document.querySelector(".lion_head");

window.addEventListener("scroll", function(event) {

    this.scrollY <= 2950 ? lionHead.classList.add('fixed') : lionHead.classList.remove('fixed')
}, false);

The Style

.lion_head{transition:all .3s  ease}
.fixed{right: -100px}

Here is the full illustration, scroll up and down to see it in action:

 var lionHead = document.querySelector(".lion_head"); window.addEventListener("scroll", function(event) { this.scrollY <= 2950 ? lionHead.classList.add('fixed') : lionHead.classList.remove('fixed') }, false); 

 :root{height: 4000px} .lion_head{ width: 150px; height: 150px; background: orange; position: fixed; top: 60px; right: 80vw; transition:all .3s ease } .fixed{right: -100px} 

 <div class=lion_head></div>