我可以用容器上的justify-content: space between来做

这个版本是固定宽度的块的最佳方法:

http://codepen.io/7iomka/pen/oxxeNE

在其他情况下-达尔加德版本

http://codepen.io/dalgard/pen/Dbnus

body { padding: 5%; } div { overflow: hidden; background-color: yellow; } ul { display: flex; flex-wrap: wrap; justify-content:center; margin: 0 -4px -4px 0; list-style: none; padding: 0; } li { flex: 1 0 200px; height: 200px; max-width:200px; min-width:200px; border-right: 4px solid black; border-bottom: 4px solid black; background-color: deeppink; } li:empty { height: 0; border: none; } *, :before, :after { box-sizing: border-box; } <div> <ul> <li>a</li> <li>b</li> <li>c</li> <li>d</li> <li>e</li> <li>f</li> <li>g</li> <li>h</li> <li>i</li> <li>j</li> <li>k</li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> </ul> </div>

这个问题用CSS网格解决了，

这个解决方案只适用于你有固定数量的列，即没有。要显示在单行中的元素

->使用网格但不指定行数，随着元素数量的增加，它包装成列并动态添加行，我在这个例子中指定了三列

->你不需要给你的子/细胞任何位置，因为它会使它修复，这是我们不想要的。

.grid-class{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  column-gap: 80px;
}

我修改了Dan Andreasson给出的示例，在元素上使用右边框来创建一个伪gutter。然后，您可以使用第n -child删除所需列网格计数的最后一个子节点上的边框。这里是一个演示https://codepen.io/JacobLett/pen/mdVoroM

/* demo only */ body { margin:0; padding:0; max-width:1024px; margin:0 auto; } .block-list { background: #ccc; border:1px solid #ccc; } .block-list .block-list__item { background: #eee; } /* demo only */ .block-list .block-list__item { min-height: 100px; margin-bottom: 1rem; } @media only screen and (min-width: 900px) { .block-list { display: -webkit-box; display: flex; flex-wrap: wrap; -webkit-box-pack: justify; justify-content: space-between; background-color: #ffffff; margin: 1em auto; } .block-list:after { content: ""; -webkit-box-flex: 1; flex: auto; } .block-list__item { height: 10em; width: 25%; box-sizing: border-box; border-right: 10px solid white; } .block-list-2 .block-list__item { width: 50%; } .block-list-2 .block-list__item:nth-child(2n) { border: none; } .block-list-3 .block-list__item { width: 33.3%; } .block-list-3 .block-list__item:nth-child(3n) { border: none; } .block-list-4 .block-list__item { width: 25%; } .block-list-4 .block-list__item:nth-child(4n) { border: none; } .block-list-5 .block-list__item { width: 20%; } .block-list-5 .block-list__item:nth-child(5n) { border: none; } .block-list-6 .block-list__item { width: 16.66%; } .block-list-6 .block-list__item:nth-child(6n) { border: none; } } <h2>2 column</h2> <div class="block-list block-list-2"> <div class="block-list__item">1 </div> <div class="block-list__item">2 </div> <div class="block-list__item">3 </div> <div class="block-list__item">4 </div> <div class="block-list__item">5 </div> <div class="block-list__item">6 </div> </div> <h2>3 column</h2> <div class="block-list block-list-3"> <div class="block-list__item">1 </div> <div class="block-list__item">2 </div> <div class="block-list__item">3 </div> <div class="block-list__item">4 </div> <div class="block-list__item">5 </div> <div class="block-list__item">6 </div> </div> <h2>4 column</h2> <div class="block-list block-list-4"> <div class="block-list__item">1 </div> <div class="block-list__item">2 </div> <div class="block-list__item">3 </div> <div class="block-list__item">4 </div> <div class="block-list__item">5 </div> <div class="block-list__item">6 </div> </div> <h2>5 column</h2> <div class="block-list block-list-5"> <div class="block-list__item">1 </div> <div class="block-list__item">2 </div> <div class="block-list__item">3 </div> <div class="block-list__item">4 </div> <div class="block-list__item">5 </div> <div class="block-list__item">6 </div> </div> <h2>6 column</h2> <div class="block-list block-list-6"> <div class="block-list__item">1 </div> <div class="block-list__item">2 </div> <div class="block-list__item">3 </div> <div class="block-list__item">4 </div> <div class="block-list__item">5 </div> <div class="block-list__item">6 </div> </div>

添加一个::之后自动填充空间。不需要污染你的HTML。下面是一个代码依赖体:http://codepen.io/DanAndreasson/pen/ZQXLXj

.grid {
  display: flex;
  flex-flow: row wrap;
  justify-content: space-between;
}

.grid::after {
  content: "";
  flex: auto;
}

简单使用Jquery/Javascript技巧添加一个空div:

if($('.exposegrid').length%3==2){
 $(".exposegrid").append('<div class="exposetab"></div>');
}