如何使用 jquery 每个函数从每个 li 获取数据?

I have a unordered list and each list element have "data-id" attribute, the idea is that using JQuery's each function iterate through each list element and get the "data-id" value and dynamically assign the position, ie to make a item slider that slides one item at a time. but on each the value of data I'm getting is "1", ie its taking value from the first element only, how do I fix it??

HTML

<div class="explore_matches">
   <p>Recent Matches</p>
   <ul class="clearfix item-slider">
       <li data-id="1" ><span>1</span></li>
       <li data-id="2" ><span>2</span></li>
       <li data-id="3" ><span>3</span></li>
       <li data-id="4" ><span>4</span></li>
       <li data-id="5" "><span>5</span></li>
       <li data-id="6" "><span>6</span></li>
       <li data-id="7" "><span>7</span></li>
       <li data-id="8" "><span>8</span></li>
    </ul>
    <button name="pre">Pre</button>
    <button name="next">Next</button>
</div>

JavaScript

var item_width = $('.item-slider').width();
var item_margin = (item_width-600)/5;
var items = $('ul.item-slider>li');

$.each(items,function(index){

    var pos = $('.item-slider > li').data('id') * 150;
    if(index === 0)     
        $(this).css("left", pos);
    else
        $(this).css("left", pos + index * item_margin);
    console.log(pos);
})

推荐答案

直接替换

var pos = $('.item-slider > li').data('id') * 150; 

与

var pos = $(this).data('id') * 150;