html - 将 flexbox 高度限制为浏览器窗口(目前它溢出导致垂直滚动)

Question

我正在尝试制作适合浏览器窗口大小的应用。

菜单的高度应适合父级的 100%，而不是屏幕的 100%。我有这个:

|---------------------------------|
| Header                          |
|---------------------------------|
||-------------------------------||
|| flex                          ||
|||--------------|               ||
||| Menu         |               ||
|||              |               ||
||| 1 item       |               ||
|||              |               ||
|||              |               ||
|||              |               ||
|||              |---------------||
  |              |
  |--------------|

我要

|---------------------------------|
| Header                          |
|---------------------------------|
||-------------------------------||
|| flex                          ||
|||--------------|               ||
||| Menu         |               ||
|||              |               ||
||| 1 item       |               ||
|||              |               ||
|||              |               ||
|||              |               ||
|||              |               ||
|||--------------|---------------||

我的代码:https://jsfiddle.net/vLbzLtyf/

<div app-context>
     <header>
       <h1>Application</h1>
     </header>

<div class="layout-flex-container row">
<div class="element">
  <aside>
    <h2>Menu</h2>
    <nav>
      <ul>
        <li>
          <span>
                          <i class="material-icons">person</i>
                          <a href="#">John Doe</a>
                      </span>
        </li>
        <li>
          <span>
                          <i class="material-icons">person</i>
                          <a href="#">Paul Smith</a>
                      </span>
        </li>
        <li>
          <span>
                          <i class="material-icons">person</i>
                          <a href="#">Jean Dupont</a>
                      </span>
        </li>
        <li>
          <span>
                          <i class="material-icons">person</i>
                          <a href="#">Xavier Lin</a>
                      </span>
        </li>
      </ul>
    </nav>
  </aside>
</div>

html,
body {
  height: 100%;
}

body {
  margin: 0;
}

div[app-context] {
  height: 100%;
}


/* ************************************************************************** */

.layout-flex-container {
  display: flex;
  align-items: stretch;
  flex-wrap: nowrap;
  height: 100%;
}

.layout-flex-container.row {
  flex-direction: row;
}

.layout-flex-container.row .element {
  flex: 0 1 auto;
  height: 100%;
}


/* ************************************************************************** */

header {
  display: flex;
  flex-wrap: nowrap;
  flex-direction: row;
  align-items: center;
  justify-content: flex-start;
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, .14), 0 3px 1px -2px rgba(0, 0, 0, .2), 0 1px 5px 0 rgba(0, 0, 0, .12);
  box-sizing: border-box;
  border: none;
  width: 100%;
  height: 128px;
  margin: 0;
  padding-bottom: 64px;
  z-index: 3;
  background-color: rgb(63, 81, 181);
  color: rgb(255, 255, 255);
}

header > h1 {
  flex: 1;
  box-sizing: border-box;
  margin: 0;
  padding: 0 40px 0 80px;
  font-family: "Roboto", "Helvetica", "Arial", sans-serif;
  font-size: 20px;
  line-height: 1;
  letter-spacing: .02em;
  font-weight: 400;
}


/* ************************************************************************** */

aside {
  height: 100%;
  width: 340px;
  background: transparent;
  color: #424242;
  z-index: 5;
}

aside > h2 {
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, .14), 0 3px 1px -2px rgba(0, 0, 0, .2), 0 1px 5px 0 rgba(0, 0, 0, .12);
  box-sizing: border-box;
  color: black;
  line-height: 64px;
  padding-left: 40px;
  margin: 0;
  font-family: "Roboto", "Helvetica", "Arial", sans-serif;
  font-size: 20px;
  letter-spacing: .02em;
  font-weight: 400;
}

aside > nav {
  height: 100%;
  background: #fafafa;
  padding-top: 16px;
  box-sizing: border-box;
}

aside > nav > ul {
  display: flex;
  flex-wrap: nowrap;
  flex-direction: column;
  align-items: flex-start;
  padding: 8px 0;
  margin: 0;
  list-style: none;
}

aside > nav > ul li {
  box-sizing: border-box;
  font-family: "Roboto", "Helvetica", "Arial", sans-serif;
  font-size: 16px;
  font-weight: 400;
  letter-spacing: .04em;
  line-height: 1;
  min-height: 48px;
  padding: 16px;
  color: rgba(0, 0, 0, .87);
  overflow: hidden;
}

我怎样才能做到这一点？

Answer 1

您需要调整您的 height: 100%在两个地方。目前，它与其他 px 相结合代码中定义的高度，这会导致浏览器窗口溢出。

取而代之的是:

.layout-flex-container {
      height: 100%;
}

aside > nav {
      height: 100%;
}

试试这个:

.layout-flex-container {
      height: calc(100% - 128px);  /* subtract the defined height of the header element */
}

aside > nav {
       height: calc(100% - 64px);  /* subtract the defined line-height of the h2 element */
}

Revised Fiddle

了解有关 CSS 的更多信息 calc W3C 的功能:

8.1. Mathematical Expressions: calc()

The calc() function allows mathematical expressions with addition (+), subtraction (-), multiplication (*), and division (/) to be used as component values. The calc() expression represents the result of the mathematical calculation it contains, using standard operator precedence rules. It can be used wherever <length>, <frequency>, <angle>, <time>, <number>, or <integer> values are allowed. (Read more.)