问我想在固定大小的div元素中填充图像滑块

EN

<div class="swiper-container thumbnails-preview" data-autoplay="0" data-loop="1"
    data-speed="500" data-center="0" data-slides-per-view="1">
    <div class="swiper-wrapper">
        <div class="swiper-slide active" data-val="0">
             <div class="img_content">
                   <img class="img-responsive"  src="img_url"alt="">
                   <img class="img-responsive"  src="img_url"alt="">
                   ...
             </div>
        </div>
         <div class="pagination pagination-hidden poin-style-1"></div>
              <div class="arr-t-3">
                    <div class="swiper-arrow-left sw-arrow"><span class="fa fa-angle-left" style="left: 10px"></span></div>
                     <div class="swiper-arrow-right sw-arrow"><span class="fa fa-angle-right" style="right: 10px"></span>
              </div>
         </div>
    </div>
</div>

    $(".img_content").each(function () {

        var parentWidth = $(this).width();
        var parentHeight = parentWidth * 0.7;

        $(this).css("height", parentHeight);
        $(this).css("overflow", "hidden");

        var target = $(this).children('img');
        var width = target.width();
        var height = target.height();

        var ratioXY = 0.5;

        var imgW = $(this).children('img').width();
        var imgH = $(this).children('img').height();


        //block size
        var block_width = $(this).closest(".swiper-container").width();
        var block_height = block_width * ratioXY;

        //image ratio
        var ratio = imgH / imgW;

        //image block size
        $(this).css("width", block_width);
        $(this).css("height", block_height);
        $(this).css("overflow", "hidden");

        if (ratio > ratioXY) {
            $(this).children('img').css("width", "100%");
            var gap = (imgH * block_width / imgW - block_height) / 2;
            $(this).children('img').css("margin-top", -gap);
        }
        else {
            $(this).children('img').css("height", "100%");
            $(this).children('img').css("max-width", 100 / ratio + "%");
            var gap = (imgW * block_height / imgH - block_width) / 2;
            $(this).children('img').css("margin-left", -gap);
        }
    });