当父元素具有固定大小时，溢出自动在子元素中不起作用

Question

我创建了一个包含 2 个孩子的固定大小的父 div，但我希望只有第二个有 overflow: auto;

不幸的是，它没有按预期工作......

这是我的sn-p：

.parent
{
	height: 200px;
	width: 100px;
	background-color: #F00;
	padding: 10px;
}

.second-child
{
	overflow: auto;
}

<div class="parent">
	<div class="first-child">
		Some content
	</div>
	<hr />
	<div class="second-child">
		"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
	</div>
</div>

有什么想法吗？

Answer 1

您可以使用max-height CSS 属性。在max-height 的帮助下，您可以设置最大高度。如果内容超过最大高度，将自动进行 Y 滚动。

代码

.parent
{
	height: 200px;
	width: 100px;
	background-color: #F00;
	padding: 10px;
}

.second-child
{
	overflow: auto;
        max-height:100px
}

<div class="parent">
	<div class="first-child">
		Some content
	</div>
	<hr />
	<div class="second-child">
		"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
	</div>
</div>

Answer 2

您应该在溢出开始之前设置一个最大值...

编辑： 将 max-height 设置为 % 以便它始终满足您不断变化的需求。我在这里保留了 80%，因为它很好地适应了二胎

.second-child
{
  max-height: 80%;
    overflow: auto;
}

现在应该好了！

.parent
{
	height: 200px;
	width: 100px;
	background-color: #F00;
	padding: 10px;
}

.second-child
{
  max-height: 80%;
	overflow: auto;
}

<div class="parent">
	<div class="first-child">
		Some content
	</div>
	<hr />
	<div class="second-child">
		"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
	</div>
</div>

Answer 3

更新：

定义一个max-height 告诉浏览器在多长时间后溢出会发生

更新 2：

1. 使容器成为表格
2. 制作另外 2 个 div 的表格行
3. 在第 2 个 div 中，将文本置于绝对位置之后的相对位置

.parent {
  height: 200px;
  width: 100px;
  background-color: #F00;
  padding: 10px;
  display: table;
}

.first-child,
.second-child {
  display: table-row;
}

.second-child {
  height: 100%;
}

.second-child-content-wrapper {
  position: relative;
  width: 100%;
  height: 100%;
}

.second-child-content {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  overflow: auto;
}

<div class="parent">
  <div class="first-child">
    Some content
  </div>
  <hr />
  <div class="second-child">
    <div class="second-child-content-wrapper">
      <div class="second-child-content">
        "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor
        in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
      </div>
    </div>
  </div>
</div>