Flexbox:包装/“蛇包装”上的反向

Ver*_*ern 9 html css flexbox

我想找到一种方法,将单个容器中的元素包装到与前一行相反方向的新行,就像一条蛇向后弯曲。我无法使用 flexbox 以及 flex-direction 和 flex-wrap 属性的任何组合来实现这一结果。

flexbox 结果与期望结果的图像比较:

flexbox 结果与期望结果的图像比较

这是一个显示 flexbox 结果与所需结果(伪造)的片段:

body {
  font: 400 14px 'Arial', sans-serif;
}

.title {
  font-size: 1em;
  padding: 20px 0;
}

.title:first-child {
  padding: 0 0 20px;
}

.flex-container, .fake-container, .fake-row {
  width: 500px;
  background: orange;
  display: flex;
}

.flex-container {
  flex-flow: row wrap; /* any combination of row/reverse & wrap/reverse */
}

.item {
  display: inline-block;
  background: purple;
  width: 80px;
  max-width: 80px;
  height: 80px;
  margin: 10px;
  line-height: 80px;
  color: white;
  font-weight: bold;
  font-size: 2em;
  text-align: center;
}

.fake-container {
  flex-flow: column nowrap;
}

.fake-row {
  flex-flow: row wrap;
  height: 100px;
}

.fake-row:nth-child(2) {
  flex-flow: row-reverse wrap;
}
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<div class="title">Flexbox result:</div>
<div class="flex-container">
  <div class="item">1</div>
  <div class="item">2</div>
  <div class="item">3</div>
  <div class="item">4</div>
  <div class="item">5</div>
  <div class="item">6</div>
  <div class="item">7</div>
</div>

<div class="title">Desired result (faked):</div>
<div class="fake-container">
  <div class="fake-row">
    <div class="item">1</div>
    <div class="item">2</div>
    <div class="item">3</div>
    <div class="item">4</div>
    <div class="item">5</div>
  </div>
  <div class="fake-row">
    <div class="item">6</div>
    <div class="item">7</div>
  </div>
</div>
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尽管我很想找到一个纯 CSS 解决方案来实现这种“蛇形包裹”,但我开始怀疑它的可能性。我确信可以使用 javascript 解决方案,但我不确定如何在不使事情过于复杂的情况下继续创建一个解决方案。

有什么简单的解决方案吗?感谢您的时间。

Tem*_*fif 7

一种类似于此解决方案的 CSS 网格解决方案,它适用于每行固定数量的元素(也就是固定数量的列)。

.flex-container {
  width: 500px;
  background: orange;
  display: grid;
  grid-template-columns:repeat(5,1fr); /*define the number of column*/
  grid-auto-flow:dense; /* this is important to fill all the space*/
  grid-gap:20px;
  padding:10px;
}

.item {
  background: purple;
  height: 80px;
  line-height: 80px;
  color: white;
  font-weight: bold;
  font-size: 2em;
  text-align: center;
}

.item:nth-child(10n + 6)  {grid-column:5}
.item:nth-child(10n + 7)  {grid-column:4}
.item:nth-child(10n + 8)  {grid-column:3}
.item:nth-child(10n + 9)  {grid-column:2}
/*.item:nth-child(10n + 10) {grid-column:1} not needed*/
/* For N = number of columns 
  .item:nth-child((2xN)n + (N+1)) { grid-column:N; }
  .item:nth-child((2xN)n + (N+2)) { grid-column:(N-1); }
  ....
  .item:nth-child((2xN)n + (2xN)) { grid-column:1; }

*/

.item:before {
  content:counter(num);
  counter-increment:num;
}
body {
  font: 400 14px 'Arial', sans-serif;
  counter-reset:num;
}
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<div class="flex-container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>
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如果你想要一个通用的解决方案,这里是一个使用 JS 和 flexbox 的解决方案。诀窍是order根据每个项目的行位置设置属性。我将依靠这个旧答案来进行大部分计算,以便找到行/列数:

//total number of element
var elems = document.querySelectorAll('.item');
var n_t = elems.length;
//width of an element
var w = parseInt(document.querySelector('.item').offsetWidth);
//full width of element with margin
var m = document.querySelector('.item').currentStyle || window.getComputedStyle(document.querySelector('.item'));
w = w + parseInt(m.marginLeft) + parseInt(m.marginRight);
//width of container
var w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
//padding of container
var c = document.querySelector('.flex-container').currentStyle || window.getComputedStyle(document.querySelector('.flex-container'));
var p_c = parseInt(c.paddingLeft) + parseInt(c.paddingRight);


var adjust = function(){
   //only the width of container will change
   w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
   //Number of columns
   nb = Math.min(parseInt((w_c - p_c) / w),n_t);
   //Number of rows
   nc = Math.ceil(n_t/nb);
   for(var j = 0;j<nb;j++) {
     for(var i = 0;i<nc;i++) {
       if(j + i*nb >= n_t) /* we exit if we reach the number of elements*/
        break
       if(i%2!=1) 
         elems[j + i*nb].style.order=j + i*nb; /* normal flow */
       else
         elems[j + i*nb].style.order=(nb - j) + i*nb; /* opposite flow */
     }
    }
}

adjust()
window.addEventListener('resize', function(){adjust()})
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.flex-container {
  background: orange;
  display: flex;
  flex-wrap:wrap;
}

.item {
  background: purple;
  height: 80px;
  width:80px;
  margin:10px;
  line-height: 80px;
  grid-gap:20px;
  color: white;
  font-weight: bold;
  font-size: 2em;
  text-align: center;
}


.item:before {
  content:counter(num);
  counter-increment:num;
}
body {
  font: 400 14px 'Arial', sans-serif;
  counter-reset:num;
}
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<div class="flex-container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>
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在某些情况下,当最后一行没有装满物品时,最后一行会有一个小问题。您可以通过向最后一个元素添加一些边距来纠正此问题

//total number of element
var elems = document.querySelectorAll('.item');
var n_t = elems.length;
//width of an element
var w = parseInt(document.querySelector('.item').offsetWidth);
//full width of element with margin
var m = document.querySelector('.item').currentStyle || window.getComputedStyle(document.querySelector('.item'));
w = w + parseInt(m.marginLeft) + parseInt(m.marginRight);
//width of container
var w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
//padding of container
var c = document.querySelector('.flex-container').currentStyle || window.getComputedStyle(document.querySelector('.flex-container'));
var p_c = parseInt(c.paddingLeft) + parseInt(c.paddingRight);


var adjust = function(){
   //only the width of container will change
   w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
   //Number of columns
   nb = Math.min(parseInt((w_c - p_c) / w),n_t);
   //Number of rows
   nc = Math.ceil(n_t/nb);
   for(var j = 0;j<nb;j++) {
     for(var i = 0;i<nc;i++) {
       if(j + i*nb >= n_t) /* we exit if we reach the number of elements*/
        break
       elems[j + i*nb].style.marginLeft='10px'; /*we rest the margin*/
       if(i%2!=1) 
         elems[j + i*nb].style.order=j + i*nb; /* normal flow */
       else {
         elems[j + i*nb].style.order=(nb - j) + i*nb; /* opposite flow */
         /*margin fix*/
         if(i == (nc - 1) && (j + i*nb == (n_t - 1)) && j<(nb-1)) {
            elems[j + i*nb].style.marginLeft=((nb*nc - n_t)*w + 10) + 'px';
         }
       }
     }
    }
}

adjust()
window.addEventListener('resize', function(){adjust()})
Run Code Online (Sandbox Code Playgroud)
.flex-container {
  background: orange;
  display: flex;
  flex-wrap:wrap;
}

.item {
  background: purple;
  height: 80px;
  width:80px;
  margin:10px;
  line-height: 80px;
  grid-gap:20px;
  color: white;
  font-weight: bold;
  font-size: 2em;
  text-align: center;
}


.item:before {
  content:counter(num);
  counter-increment:num;
}
body {
  font: 400 14px 'Arial', sans-serif;
  counter-reset:num;
}
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<div class="flex-container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>
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您只需更改if(i%2!=1)为即可轻松切换到另一个方向if(i%2!=0)

//total number of element
var elems = document.querySelectorAll('.item');
var n_t = elems.length;
//width of an element
var w = parseInt(document.querySelector('.item').offsetWidth);
//full width of element with margin
var m = document.querySelector('.item').currentStyle || window.getComputedStyle(document.querySelector('.item'));
w = w + parseInt(m.marginLeft) + parseInt(m.marginRight);
//width of container
var w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
//padding of container
var c = document.querySelector('.flex-container').currentStyle || window.getComputedStyle(document.querySelector('.flex-container'));
var p_c = parseInt(c.paddingLeft) + parseInt(c.paddingRight);


var adjust = function(){
   //only the width of container will change
   w_c = parseInt(document.querySelector('.flex-container').offsetWidth);
   //Number of columns
   nb = Math.min(parseInt((w_c - p_c) / w),n_t);
   //Number of rows
   nc = Math.ceil(n_t/nb);
   for(var j = 0;j<nb;j++) {
     for(var i = 0;i<nc;i++) {
       if(j + i*nb >= n_t) /* we exit if we reach the number of elements*/
        break
       elems[j + i*nb].style.marginLeft='10px'; /*we rest the margin*/
       if(i%2!=0) 
         elems[j + i*nb].style.order=j + i*nb; /* normal flow */
       else {
         elems[j + i*nb].style.order=(nb - j) + i*nb; /* opposite flow */
         /*margin fix*/
         if(i == (nc - 1) && (j + i*nb == (n_t - 1)) && j<(nb-1)) {
            elems[j + i*nb].style.marginLeft=((nb*nc - n_t)*w + 10) + 'px';
         }
       }
     }
    }
}

adjust()
window.addEventListener('resize', function(){adjust()})
Run Code Online (Sandbox Code Playgroud)
.flex-container {
  background: orange;
  display: flex;
  flex-wrap:wrap;
}

.item {
  background: purple;
  height: 80px;
  width:80px;
  margin:10px;
  line-height: 80px;
  grid-gap:20px;
  color: white;
  font-weight: bold;
  font-size: 2em;
  text-align: center;
}


.item:before {
  content:counter(num);
  counter-increment:num;
}
body {
  font: 400 14px 'Arial', sans-serif;
  counter-reset:num;
}
Run Code Online (Sandbox Code Playgroud)
<div class="flex-container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>
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