元素超出横向滚动(子元素无需确定总宽度)

.parent{
    width: 100%;    //显示的宽度
    overflow-x: scroll;  
    overflow-y: hidden; 
    white-space: nowrap;   //使只显示在一行。不换行
}
.child{
  width:100px;
  height:50px;
  display:inline-block;       
}

<div class="parent">
    <div class="child">1</div>
    <div class="child">2</div>
    <div class="child">3</div>
    ...
</div>