[前端插件] js傳回頂部 效果實作

需要 jQuery

參考

http://www.jb51.net/article/48203.htm css:

#goTop{
    position:absolute;
    display:none;
    width:50px;
    height:48px;
    background:#fff url(static/img/gotop.png) no-repeat 16px 15px;
    border:solid 1px #f9f9f8;border-radius:6px;box-shadow:0 1px 1px rgba(0, 0, 0, 0.2);cursor:pointer
}
#goTop:hover{
    height:50px;
    background-position:16px 16px;
    box-shadow:0 1px 1px rgba(0, 0, 0, 0.3)
}
           

html:

<div id="goTop" class="goTop"></div>
           

Javascript:

//傳回頂部
$(window).scroll(function(){
    var sc=$(window).scrollTop();
    var rwidth=$(window).width()+$(document).scrollLeft();
    var rheight=$(window).height()+$(document).scrollTop();
    if(sc>0){
        $("#goTop").css("display","block");
        $("#goTop").css("left",(rwidth-80)+"px");
        $("#goTop").css("top",(rheight-120)+"px");
    }else{
        $("#goTop").css("display","none");
    }
});
$("#goTop").click(function(){
    $('body,html').animate({scrollTop:0},300);
});