如何更改 flexbox 换行？

Question

我的应用程序中有一个带有动态渲染卡片（从 1-10 个卡片渲染每个 api 调用）的响应式 flexbox 框。除了包装方式之外，它几乎完全符合我的要求。

假设我渲染了 10 张卡片，如果我调整屏幕大小使其变成例如4-4-2 最后两张卡片居中，我希望它可以换行，所以最后两张卡片从左侧开始，并且与上面的卡片一样间距相等。你怎么能这样做？

编辑进一步阐述：假设我将大小调整为 1-1-1-1-1-1-1-1-1-1 ，卡片应该居中，我仍然需要居中，但我想要如果它变成 4-4-2 或 3-3-2 等，则从左侧包装最后 2 张牌。

https://codepen.io/hyrosian/pen/EXKZJz

.card {
    text-align: center;
    box-shadow: 0 1px 3px 0 #d4d4d5, 0 0 0 1px #d4d4d5;
    max-width: 300px;
    margin: 2rem;
    padding-bottom: 1rem;
}
.container {
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;

}

.recipe-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around
}

<div class="container">
  <div class="recipe-grid">
    
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
    
    
  </div>
</div>
  

Answer 1

如果使用 Flexbox，并且不使用脚本，您可以创建 ghost 元素，以便它们填充最后一行的空间。

因此，对于可能的 4 列长度，您需要 3 个 ghost 元素，依此类推。

也可以使用伪元素，这会将所需的 ghost 减少 2。

.card {
    text-align: center;
    box-shadow: 0 1px 3px 0 #d4d4d5, 0 0 0 1px #d4d4d5;
    max-width: 300px;
    margin: 2rem;
    padding-bottom: 1rem;
}
.card:empty {
    width: 300px;
    box-shadow: none;
    margin: 2rem;
    padding-bottom: 0;
}

.container {
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;

}

.recipe-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around
}

<div class="container">
  <div class="recipe-grid">
    
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
     
    <div class="card">
      <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
      <h3> Egg beef sandwich </h3>
      <p> 604 kcal - totally vegan </p>
    </div>
    

    <div class="card"></div>
    <div class="card"></div>
    <div class="card"></div>
    
  </div>
</div>

---

更新

由于您使用justify-content: space-around，您也可以这样做，在card 周围添加一个额外的包装器，将其居中，然后通过媒体查询，使包装器根据项目的数量填充行每行。

注意，由于不能在媒体查询中使用CSS calc，所以值是基于1rem等于16px，所以第一个计算如下：300px + (2rem * 2) = 728px等等。因此，如果您的浏览器在 root 元素上的默认字体大小不是16px，您要么将其设置为该值，要么重新计算查询值

.card {
  text-align: center;
  box-shadow: 0 1px 3px 0 #d4d4d5, 0 0 0 1px #d4d4d5;
  max-width: 300px;
  margin: 2rem;
  padding-bottom: 1rem;
}
.container {
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}
.recipe-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
}
.recipe-grid .card-wrapper {
  display: flex;
  justify-content: center;
  width: 100%;
}
@media (min-width:  728px) { .recipe-grid .card-wrapper { width: 50%;     } }
@media (min-width: 1092px) { .recipe-grid .card-wrapper { width: 33.333%; } }
@media (min-width: 1456px) { .recipe-grid .card-wrapper { width: 25%;     } }
@media (min-width: 1820px) { .recipe-grid .card-wrapper { width: 20%;     } }

<div class="container">
  <div class="recipe-grid">
    
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
     
    <div class="card-wrapper">
      <div class="card">
        <img src="https://www.edamam.com/web-img/40b/40bfe88c879112dfc1786938c6c36832.jpg">
        <h3> Egg beef sandwich </h3>
        <p> 604 kcal - totally vegan </p>
      </div>
    </div>
    
  </div>
</div>

---

最后，我还想提一下这些帖子，how-to-center-a-flex-container-but-left-align-flex-items 和 can-i-change-the-justify-content-value-depending-on-the-number-of-elements-in（可能被视为与此重复），因为它很好地解释了 Flexbox 的工作原理，因为它能够同时包装和中心项目，以及一些比我给出的解决方案更多的解决方案。

Answer 2

按如下方式更改您的 CSS：

.recipe-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start
}

如果需要，可以为卡片添加边距。