css使Img图片居中显示

<div class="flex-center listing-img">    <img v-if="item.imgUrl" v-bind:src="item.imgUrl" alt="not find picture">    <img v-if="!item.imgUrl" src="../../assets/img/detail-not-image.png"alt="not find picture" v-sf-img></div> img1是默认显示图片.listing-img{
　　width: 100%;   min-height: 270px;   max-height: 320px;}.listing-img>img{　　display: inline-block;   height: auto;   max-width: 100%;   max-height: 320px;}.flex-center {　　display: flex;　　justify-content: center;　　align-items: center;}