当子项是使用宽高比的按钮时，Flexbox 问题

Question

我在数字输入组件中使用

flex

来在输入本身旁边呈现自定义“+”和“-”按钮。按钮使用

aspect-ratio: 1/1;

来确保它们始终是方形的，但我似乎无法让按钮的容器遵守这一点。相反，按钮溢出了容器，几乎就像容器在没有

aspect-ratio

属性的情况下测量其大小一样。当我删除该属性时，容器会以适当的大小呈现。

一些示例代码：

.input-interior {
    box-shadow: 0 1px 0 blue;
    box-sizing: border-box;
    display: flex;
    flex-grow: 1;
    position: relative;
    width: 600px;
}

.input-container {
    flex-grow: 1;
    min-width: 0;
}

input {
    appearance: textfield;
    background-color: transparent;
    border: none;
    box-shadow: none;
    box-sizing: border-box;
    color: rgb(15 15 15);
    height: 80px;
    margin: 0;
    outline: none;
    padding-left: 8px;
    padding-right: 8px;
    padding-top: 5px;
    padding: 0;
    width: 100%;
}

.input-actions {
    box-shadow: 0 0 0 1px green;
    box-sizing: border-box;
    column-gap: 8px;
    display: flex;
    flex-shrink: 0;
    padding: 8px;
}

button {
    border: none;
    margin: 0;
    padding: 0;
    aspect-ratio: 1 / 1;
    min-height: 44px;
    align-items: center;
    display: flex;
    justify-content: center;
    min-width: auto;
    width: auto;
}

<div class="input-interior">
    <div class="input-container">
        <input min="0" step="1" type="number" value="0" />
    </div>
    <div class="input-actions">
        <button type="button">-</button>
        <button type="button">+</button>
    </div>
</div>

如何让

.input-actions

容器适应其子级的动态大小？

Answer 1

简短回答：

min-height

应等于整个可用高度。

button {
    min-height: 64px;
}

.input-interior {
  box-shadow: 0 1px 0 blue;
  box-sizing: border-box;
  display: flex;
  flex-grow: 1;
  position: relative;
  width: 600px;
}

.input-container {
  flex-grow: 1;
  min-width: 0;
}

input {
  appearance: textfield;
  background-color: transparent;
  border: none;
  box-shadow: none;
  box-sizing: border-box;
  color: rgb(15 15 15);
  height: 80px;
  margin: 0;
  outline: none;
  padding-left: 8px;
  padding-right: 8px;
  padding-top: 5px;
  padding: 0;
  width: 100%;
}

.input-actions {
  box-shadow: 0 0 0 1px green;
  box-sizing: border-box;
  column-gap: 8px;
  display: flex;
  flex-shrink: 0;
  padding: 8px;
}

button {
  border: none;
  margin: 0;
  padding: 0;
  aspect-ratio: 1 / 1;
  min-height: 64px;
  align-items: center;
  display: flex;
  justify-content: center;
  min-width: auto;
  width: auto;
}

<div class="input-interior">
  <div class="input-container">
    <input min="0" step="1" type="number" value="0" />
  </div>
  <div class="input-actions">
    <button type="button">-</button>
    <button type="button">+</button>
  </div>
</div>

详情

当只有

min-height

时，

.input-actions

容器也将其用作按钮的宽度（自

aspect-ratio: 1/1

起），并以此为基础构建自己的宽度：

112px = (2 * button min-height 44px) + (2 * container padding 8px) + (column-gap 8px)

设置

min-height: 100%

似乎很合理，但在这种情况下，容器将变得甚至小于 40px（取决于字体规格），因为它需要绝对单位，而不是相对单位。

CSS 变量和

calc()

可用于使高度可在一处设置：

.input-interior {
  --input-height: 80px;
  box-shadow: 0 1px 0 blue;
  box-sizing: border-box;
  display: flex;
  flex-grow: 1;
  position: relative;
  width: 600px;
}

.input-container {
  flex-grow: 1;
  min-width: 0;
}

input {
  appearance: textfield;
  background-color: transparent;
  border: none;
  box-shadow: none;
  box-sizing: border-box;
  color: rgb(15 15 15);
  height: var(--input-height);
  margin: 0;
  outline: none;
  padding-left: 8px;
  padding-right: 8px;
  padding-top: 5px;
  padding: 0;
  width: 100%;
}

.input-actions {
  box-shadow: 0 0 0 1px green;
  box-sizing: border-box;
  column-gap: 8px;
  display: flex;
  flex-shrink: 0;
  padding: 8px;
}

button {
  border: none;
  margin: 0;
  padding: 0;
  aspect-ratio: 1 / 1;
  min-height: calc(var(--input-height) - 8px * 2);
  align-items: center;
  display: flex;
  justify-content: center;
  min-width: auto;
  width: auto;
}

<div class="input-interior">
  <div class="input-container">
    <input min="0" step="1" type="number" value="0" />
  </div>
  <div class="input-actions">
    <button type="button">-</button>
    <button type="button">+</button>
  </div>
</div>