使 div 在 Flexbox 内可滚动

Question

我有一个包含 2 个窗格的侧边栏。当我垂直调整窗口大小时，我希望顶部窗格动态调整大小，而底部窗格保持固定大小。当侧边栏的总高度小于两个窗格时，我希望顶部窗格缩小到小于其内容，并变得可滚动。

预期行为与 VS Code 的侧边栏相同。

目前，调整大小时，顶部窗格会“推”底部窗格。

document.addEventListener("DOMContentLoaded", () => {
  const listItem = document.querySelector(".top-panel .list-item");
  for (let i = 0; i < 25; i++) {
    listItem.parentNode.appendChild(listItem.cloneNode(true));
  }
});

html,
body {
  margin: 0;
}

.main {
  margin-left: 12rem;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 12rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-right: 1px solid #454545;
}

.top-panel {
  flex-shrink: 1;
  display: flex;
  flex-direction: column;
}

.bottom-panel {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

.header {
  background-color: #ababbc;
  font-weight: 700;
}

.panel-top .list {
  flex-shrink: 1;
  overflow-y: auto;
}

.panel-bottom .list {
  flex-shrink: 0;
}

.list-item {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

<aside class="sidebar">
  <div class="top-panel">
    <div class="header">Top panel</div>
    <div class="list">
      <div class="list-item"><span>https://example.com/users/helloworld</span></div>
      <!-- copied 25 times in the JS -->
    </div>
  </div>
  <div class="bottom-panel">
    <div class="header">Bottom panel</div>
    <div class="list">
      <div class="list-item"><span>Lorem</span></div>
      <div class="list-item"><span>Ipsum</span></div>
    </div>
  </div>
</aside>
<main class="main">Main content</main>

在代码片段中使用“整页”来查看调整大小行为。

Answer 1

您可以添加overflow-y: auto到顶部面板，以便仅在必要时显示滚动条。

height: 100px您还可以通过添加示例向底部面板添加固定大小。顶部面板将自动缩小以适应剩余空间。

document.addEventListener("DOMContentLoaded", () => {
  const listItem = document.querySelector(".top-panel .list-item");
  for (let i = 0; i < 25; i++) {
    listItem.parentNode.appendChild(listItem.cloneNode(true));
  }
});

html,
body {
  margin: 0;
}

.main {
  margin-left: 12rem;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 12rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-right: 1px solid #454545;
}

.top-panel {
  overflow-y: auto;
  flex-shrink: 1;
  display: flex;
  flex-direction: column;
}

.bottom-panel {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

.header {
  background-color: #ababbc;
  font-weight: 700;
}

.panel-top .list {
  flex-shrink: 1;
  overflow-y: auto;
}

.panel-bottom .list {
  flex-shrink: 0;
}

.list-item {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

<aside class="sidebar">
  <div class="top-panel">
    <div class="header">Top panel</div>
    <div class="list">
      <div class="list-item"><span>https://example.com/users/helloworld</span></div>
      <!-- copied 25 times in the JS -->
    </div>
  </div>
  <div class="bottom-panel">
    <div class="header">Bottom panel</div>
    <div class="list">
      <div class="list-item"><span>Lorem</span></div>
      <div class="list-item"><span>Ipsum</span></div>
    </div>
  </div>
</aside>
<main class="main">Main content</main>