flex孩子长大了父母

Question

如何在不设置静态高度值且没有绝对位置的情况下强制将绿色框包含在红色框中？

我想缩小内容以适应父级。

允许缩小内容（本例中的视频）并允许滚动条。

.my-box {
  height: 300px;
  width: 600px;
  background: red;
  padding: 5px;
}
.content-box {
  background: blue;
}
.col {
  display: flex;
  flex-direction: column;
  justify-content: space-between
}
.box-shrink {
  flex: 0 1 auto;
  background: green;
  padding: 5px;
  margin: 5px;
}
.box-grow {
  flex: 1 0 auto;
  background: green;
  padding: 5px;
  margin: 5px;
}
video {
  max-height: 100%;
  max-width: 100%;
  margin: auto;
  display: block;
}

<div class="my-box col">
  <div class="box-shrink">
    small sized static content
  </div>
  <div class="content-box box-grow">
    <video controls>
      <source src="http://techslides.com/demos/sample-videos/small.webm" type="video/webm">
    </video>
  </div>
  <div class="box-shrink">
    small sized static content
  </div>
</div>

Answer 1

解决方案＃1 - 没有滚动

而不是视频容器上的flex: 1 0 auto，只需使用flex: 1即可。这会根据可用空间调整项目的大小，而不是内容的固有高度。

然后，因为flex项目不能小于其内容的大小 - min-height: auto是默认值 - 添加min-height: 0以允许项目缩小以适合容器内部。

.box-grow {
  flex: 1; /* formerly flex: 1 0 auto; */
  background: green;
  padding: 5px;
  margin: 5px;
  min-height: 0; /* new */
}

.my-box {
  height: 300px;
  width: 600px;
  background: red;
  padding: 5px;
}
.content-box {
  background: blue;
}
.col {
  display: flex;
  flex-direction: column;
  justify-content: space-between
}
.box-shrink {
  flex: 0 1 auto;
  background: green;
  padding: 5px;
  margin: 5px;
}
.box-grow {
  flex: 1; /* formerly flex: 1 0 auto; */
  background: green;
  padding: 5px;
  margin: 5px;
  min-height: 0; /* new */
}
video {
  max-height: 100%;
  max-width: 100%;
  margin: auto;
  display: block;
}

<div class="my-box col">
  <div class="box-shrink">
    small sized static content
  </div>
  <div class="content-box box-grow">
    <video controls>
      <source src="http://techslides.com/demos/sample-videos/small.webm" type="video/webm">
    </video>
  </div>
  <div class="box-shrink">
    small sized static content
  </div>
</div>

解决方案＃2 - 使用滚动

或者，提供与上面相同的视频容器overflow: auto，但保持视频全宽。您需要启用flex-shrink才能生效。

.box-grow {
  flex: 1 1 auto; /* formerly flex: 1 0 auto; */
  background: green;
  padding: 5px;
  margin: 5px;
  overflow: auto; /* new */
}

.my-box {
  height: 300px;
  width: 600px;
  background: red;
  padding: 5px;
}
.content-box {
  background: blue;
}
.col {
  display: flex;
  flex-direction: column;
  justify-content: space-between
}
.box-shrink {
  flex: 0 1 auto;
  background: green;
  padding: 5px;
  margin: 5px;
}
.box-grow {
  flex: 1 1 auto; /* formerly flex: 1 0 auto; */
  background: green;
  padding: 5px;
  margin: 5px;
  overflow: auto; /* new */
}
video {
  max-height: 100%;
  max-width: 100%;
  margin: auto;
  display: block;
}

<div class="my-box col">
  <div class="box-shrink">
    small sized static content
  </div>
  <div class="content-box box-grow">
    <video controls>
      <source src="http://techslides.com/demos/sample-videos/small.webm" type="video/webm">
    </video>
  </div>
  <div class="box-shrink">
    small sized static content
  </div>
</div>

这两种解决方案都在这里详细解释：

• Why doesn't flex item shrink past content size?

Answer 2

正如您所说，允许收缩内容（本例中的视频）并允许滚动条。如何将overflow:auto;放在.box-grow上，并将flex-shrink: 1;设置为flex: 1 1 auto; 或者，如果您设置flex: 1 1 100%;视频将适合.box-grow课程的中心，则还需要overflow:auto。

.my-box {
    height: 300px;
    width: 600px;
    background: red;
    padding: 5px;
}

.content-box {
    background: blue;
            
}

.col {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    
}

.box-shrink {
    flex: 0 1 auto;
    background: green;
    padding: 5px;
    margin: 5px;
}

.box-grow {
    flex: 1 1 auto;  /* Set the shrik 1 which is by default */
    background: green;
    padding: 5px;
    margin: 5px; 
    overflow:auto; /* Overflow will be needed if you set flex:1 1 100%*/
}

video {
    max-height: 100%;
    max-width: 100%;
    margin: auto;
    display: block;
}

<div class="my-box col">
    <div class="box-shrink">
        small sized static content
    </div>
    <div class="content-box box-grow">
        <video controls>
            <source src="http://techslides.com/demos/sample-videos/small.webm" type="video/webm">
        </video>
    </div>
    <div class="box-shrink">
        small sized static content
    </div>
</div>