calc() with jQuery (background-position)

Question

如何将 CSS calc(( 替换为 jQuery？

var scrollPos = $(window).scrollTop(),
posY = Math.floor(0.2 * scrollPos);
$('.background-layer').css('background-position', '50% calc(50% + ' + posY + 'px)');

Answer 1

这可能有助于您：

<div class="lala">
sdasd
</div>
var posY=50;
$(document).ready(function(){
$(".lala").css('background-position-y',"50%").css('background-position-
y','+='+posY+'px')
});

https://jsfiddle.net/m5946szm/1/