html
<ul class="dropdown-menu img-table-ul">
<li><img alt="" src="/static/upload/image/201708/d366cbd8-d773-47e0-80db-572e39bbdeaf.jpg"></li>
</ul>
首先給外層ul寫上樣式
width: 300px;
height: 200px;
overflow: hidden;
爲了將圖片等比縮小,並且高度不會被切割。給img元素寫樣式
img{
//max-width: 100%;
//max-height: 190px;
width:auto;
height:auto;
max-width:100%;
max-height:100%;
}