Flexbox：Alternate＆＃34; row＆＃34;和＃34;行反转＆＃34;根据行号

Question

我正在尝试使用Flexbox创建响应式布局，这样我就可以将方向row和row-reverse交替使用。

也许你可以通过一些图片更好地理解它（注意方框的顺序）：

调整大小：

或者仍然：

你可以想象一个穿过每个盒子的箭头，它必须能够按照数字序列（如蛇）经过1到8个。

如何使用flexbox实现它？

我想我可以使用order CSS属性，但我想念一种动态的设置方法。我不认为我可以用JavaScript实现这个结果，因为没有办法获得动态行的数字（除了丑陋的黑客，我想避免它们）。那么，你有什么想法吗？

谢谢。

如果您想根据我的代码编写示例，可以使用：

＆＃13;

＆＃13;

.flexbox-container {
  display: flex;
  flex-wrap: wrap;
}

.flex-item {
  width: 380px;
  height: 100px;
  background: red;
  margin: 5px;
  
  font-family: sans-serif;
  color: white;
  text-align: center;
  font-size: 2em;
  line-height: 150%;
}

＆＃13;

<div class="flexbox-container">
  <div class="flex-item">1</div>
  <div class="flex-item">2</div>
  <div class="flex-item">3</div>
  <div class="flex-item">4</div>
  <div class="flex-item">5</div>
  <div class="flex-item">6</div>
  <div class="flex-item">7</div>
  <div class="flex-item">8</div>
</div>

＆＃13;

＆＃13;

＆＃13;

Answer 1

我能看到这种情况的唯一方法是手动设置顺序，然后使用媒体查询断点 - 这是一个例子

.flexbox-container {
  display: flex;
  flex-wrap: wrap;
}

.flex-item {
  width: calc(50% - 10px);
  height: 100px;
  background: red;
  margin: 5px;
  font-family: sans-serif;
  color: white;
  text-align: center;
  font-size: 2em;
  line-height: 150%;
}

.flex-item:nth-child(1) {
  order: 1;
}

.flex-item:nth-child(2) {
  order: 2;
}

.flex-item:nth-child(3) {
  order: 4;
}

.flex-item:nth-child(4) {
  order: 3;
}

.flex-item:nth-child(5) {
  order: 5;
}

.flex-item:nth-child(6) {
  order: 6;
}

.flex-item:nth-child(7) {
  order: 8;
}

.flex-item:nth-child(8) {
  order: 7;
}

@media only screen and (max-width: 768px) {
  .flex-item {
    width: calc(33.33333% - 10px);
  }
  .flex-item:nth-child(1) {
    order: 1;
  }
  .flex-item:nth-child(2) {
    order: 2;
  }
  .flex-item:nth-child(3) {
    order: 3;
  }
  .flex-item:nth-child(4) {
    order: 6;
  }
  .flex-item:nth-child(5) {
    order: 5;
  }
  .flex-item:nth-child(6) {
    order: 4;
  }
  .flex-item:nth-child(7) {
    order: 7;
  }
  .flex-item:nth-child(8) {
    order: 8;
  }

<div class="flexbox-container">
  <div class="flex-item">1</div>
  <div class="flex-item">2</div>
  <div class="flex-item">3</div>
  <div class="flex-item">4</div>
  <div class="flex-item">5</div>
  <div class="flex-item">6</div>
  <div class="flex-item">7</div>
  <div class="flex-item">8</div>
</div>

Answer 2

鉴于项目具有已知宽度的事实，可以使用order和媒体查询来完成，而不是使用row / reverse-row，除非每行都有一个包装，赢了在你的情况下是不可能的。

Stack snippet

body {margin: 0}

.flexbox-container {
  display: flex;
  flex-wrap: wrap;
}

.flex-item {
  width: 380px;
  height: 100px;
  background: red;
  margin: 5px;
  font-family: sans-serif;
  color: white;
  text-align: center;
  font-size: 2em;
  line-height: 150%;
}
@media (min-width: 796px) {
  .flex-item:nth-child(3)   { order: 2; }
  .flex-item:nth-child(4)   { order: 1; }
  .flex-item:nth-child(n+5) { order: 2; }  
  .flex-item:nth-child(7)   { order: 4; }
  .flex-item:nth-child(8)   { order: 3; }
}
@media (min-width: 1176px) {
  .flex-item:nth-child(3)   { order: 0; }
  .flex-item:nth-child(4)   { order: 3; }
  .flex-item:nth-child(5)   { order: 2; }
  .flex-item:nth-child(6)   { order: 1; }
  .flex-item:nth-child(n+7) { order: 3; }
  .flex-item:nth-child(8)   { order: 3; }
}
@media (min-width: 1556px) {
  .flex-item:nth-child(3)   { order: 0; }
  .flex-item:nth-child(4)   { order: 0; }
  .flex-item:nth-child(5)   { order: 4; }
  .flex-item:nth-child(6)   { order: 3; }
  .flex-item:nth-child(7)   { order: 2; }
  .flex-item:nth-child(8)   { order: 1; }
}

<div class="flexbox-container">
  <div class="flex-item">1</div>
  <div class="flex-item">2</div>
  <div class="flex-item">3</div>
  <div class="flex-item">4</div>
  <div class="flex-item">5</div>
  <div class="flex-item">6</div>
  <div class="flex-item">7</div>
  <div class="flex-item">8</div>
</div>

如果项目的大小未知，则这是一个jQuery版本。

注意，分配order值需要一次完成，否则它将无法工作，就像一次开始更改一个项目的值一样，该更改将被执行立即并将影响下一个项目的位置。

Codepen demo

Stack snippet

(function ($) {
  //  preload object array to gain performance
  var $items = $('.flexbox-container .flex-item');
    
  //  run at resize
  $( window ).resize(function() {
    $.fn.setOrder(false,0);   
  });

  $.fn.setOrder = function(reverse,idx) {

    var $order = [];
    
    $items.each(function(i, obj) {    

      //  did top value changed
      if (i != 0 && $items.eq(i - 1).offset().top != $(obj).offset().top) {
        reverse = !reverse;
        //  insert index when reverse
        idx = i;
      }
      if (reverse) {
        $order.splice(idx, 0, i);
      } else {
        $order.push(i);
      }
    });
    
    //  set item's order
    $items.css('order', function(i, val) {
        return $order[i];
    });    
  }
  
  //  run at load
  $.fn.setOrder(false,0);

}(jQuery));

.flexbox-container {
  display: flex;
  flex-wrap: wrap;
}

.flex-item {
  width: 200px;
  height: 100px;
  background: red;
  margin: 5px;
  font-family: sans-serif;
  color: white;
  text-align: center;
  font-size: 2em;
  line-height: 150%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="flexbox-container">
  <div class="flex-item">1</div>
  <div class="flex-item">2</div>
  <div class="flex-item">3</div>
  <div class="flex-item">4</div>
  <div class="flex-item">5</div>
  <div class="flex-item">6</div>
  <div class="flex-item">7</div>
  <div class="flex-item">8</div>
</div>