# max-width

max-width 属性用来给元素设置最大宽度值。定义了 max-width 的元素会在达到 max-width 值之后避免进一步按照 width 属性设置变大。

# uni-app x 兼容性

Web Android iOS HarmonyOS HarmonyOS(Vapor)
4.0 3.9 4.11 4.61 5.0

# 语法

max-width: <viewport-length>;

# 值限制

  • length

# max-width 的属性值

名称 兼容性 描述
fit-content
与 max-content 等价。
max-content
元素的最大宽度可以扩展到内容的最大宽度。
min-content
元素的最大宽度限制在内容的最小宽度之内。
auto
浏览器将通过计算为指定元素选择一个 max-width 值。
none
元素未设置最大值

# 默认值

none

# 示例

示例为hello uni-app x alpha分支,与最新HBuilderX Alpha版同步。与最新正式版同步的master分支示例另见

扫码体验(手机浏览器跳转到App直达页)

示例

<template>
  <!-- #ifdef APP -->
  <scroll-view style="flex: 1">
  <!-- #endif -->
    <view style="flex-grow: 1;">
      <view>
        <text>max-width: 200px</text>
        <view class="common" style="max-width: 200px;">
          <text>width: 400px</text>
        </view>
        <text>拍平</text>
        <view class="common" style="max-width: 200px;" flatten>
          <text>width: 400px</text>
        </view>
      </view>

      <view class="uni-common-mt">
        <text class="uni-title-text">setProperty 设置与 getPropertyValue 获取 max-width </text>
      </view>

      <!-- 普通版本 -->
      <view class="test-container">
        <view class="test-item">
          <text class="uni-subtitle-text">view 组件</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActual}}</text>
          <view class="test-box">
            <view ref="viewRef" class="common-dynamic test-view" :style="{ maxWidth: maxWidth }">
              <text>view</text>
            </view>
          </view>
        </view>

        <view class="test-item">
          <text class="uni-subtitle-text">text 组件</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActualText}}</text>
          <view class="test-box">
            <text ref="textRef" class="common-dynamic test-text" :style="{ maxWidth: maxWidth }">text</text>
          </view>
        </view>

        <view class="test-item">
          <text class="uni-subtitle-text">image 组件</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActualImage}}</text>
          <view class="test-box">
            <image ref="imageRef" class="common-dynamic test-image" :style="{ maxWidth: maxWidth }" src="/static/test-image/logo.png"></image>
          </view>
        </view>
      </view>

      <!-- 拍平版本 -->
      <view class="test-container">
        <view class="test-item">
          <text class="uni-subtitle-text">view 组件拍平</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActualFlat}}</text>
          <view class="test-box">
            <view ref="viewRefFlat" class="common-dynamic test-view-flatten" :style="{ maxWidth: maxWidth }" flatten>
              <text class="common-text">view</text>
            </view>
          </view>
        </view>

        <view class="test-item">
          <text class="uni-subtitle-text">text 组件拍平</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActualTextFlat}}</text>
          <view class="test-box">
            <text ref="textRefFlat" class="common-dynamic test-text-flatten" :style="{ maxWidth: maxWidth }" flatten>text</text>
          </view>
        </view>

        <view class="test-item">
          <text class="uni-subtitle-text">image 组件拍平</text>
          <text class="uni-info">设置值: {{maxWidth}}</text>
          <text class="uni-info">获取值: {{maxWidthActualImageFlat}}</text>
          <view class="test-box">
            <image ref="imageRefFlat" class="common-dynamic test-image-flatten" :style="{ maxWidth: maxWidth }" flatten src="/static/test-image/logo.png"></image>
          </view>
        </view>
      </view>

      <view class="uni-common-mt uni-common-mb">
        <text class="uni-tips">第一个枚举值,'' (空字符串) - 空值情况</text>
        <enum-data :items="maxWidthEnum" title="max-width 枚举值" @change="radioChangeMaxWidth" :compact="true"></enum-data>
        <input-data :defaultValue="maxWidth" title="max-width 自定义值" type="text" @confirm="inputChangeMaxWidth"></input-data>
      </view>

    </view>
  <!-- #ifdef APP -->
  </scroll-view>
  <!-- #endif -->
</template>

<script setup lang="uts">
  import { ItemType } from '@/components/enum-data/enum-data-types'

  const maxWidthEnum: ItemType[] = [
    { value: 0, name: '' },
    { value: 1, name: '0' },
    { value: 2, name: '0px' },
    { value: 3, name: '50px' },
    { value: 4, name: '120px' },
    { value: 5, name: '80rpx' },
    { value: 6, name: 'none' }
  ]

  const maxWidth = ref('100px')
  const maxWidthActual = ref('')
  const maxWidthActualText = ref('')
  const maxWidthActualImage = ref('')
  const maxWidthActualFlat = ref('')
  const maxWidthActualTextFlat = ref('')
  const maxWidthActualImageFlat = ref('')
  const viewRef = ref(null as UniElement | null)
  const textRef = ref(null as UniTextElement | null)
  const imageRef = ref(null as UniImageElement | null)
  const viewRefFlat = ref(null as UniElement | null)
  const textRefFlat = ref(null as UniTextElement | null)
  const imageRefFlat = ref(null as UniImageElement | null)

  const getPropertyValues = () => {
    maxWidthActual.value = viewRef.value?.style.getPropertyValue('max-width') ?? ''
    maxWidthActualFlat.value = viewRefFlat.value?.style.getPropertyValue('max-width') ?? ''
    maxWidthActualText.value = textRef.value?.style.getPropertyValue('max-width') ?? ''
    maxWidthActualTextFlat.value = textRefFlat.value?.style.getPropertyValue('max-width') ?? ''
    maxWidthActualImage.value = imageRef.value?.style.getPropertyValue('max-width') ?? ''
    maxWidthActualImageFlat.value = imageRefFlat.value?.style.getPropertyValue('max-width') ?? ''
  }

  const changeMaxWidth = (value: string) => {
    maxWidth.value = value
    viewRef.value?.style.setProperty('max-width', value)
    viewRefFlat.value?.style.setProperty('max-width', value)
    textRef.value?.style.setProperty('max-width', value)
    textRefFlat.value?.style.setProperty('max-width', value)
    imageRef.value?.style.setProperty('max-width', value)
    imageRefFlat.value?.style.setProperty('max-width', value)
    // 使用 nextTick 确保样式已应用后再获取值
    nextTick(() => {
      getPropertyValues()
    })
  }

  const radioChangeMaxWidth = (index: number) => {
    const selectedItem = maxWidthEnum.find((item): boolean => item.value === index)
    if (selectedItem != null) {
      changeMaxWidth(selectedItem.name)
    }
  }

  function inputChangeMaxWidth(value: string) {
    changeMaxWidth(value)
  }

  onReady(() => {
    getPropertyValues()
  })

  defineExpose({
    radioChangeMaxWidth
  })
</script>

<style>
  .common {
    width: 400px;
    height: 80px;
    background-color: cyan;
    justify-content: center;
    align-items: center;
  }

  .common-text{
    width: 50px;
  }

  .common-dynamic {
    width: 100px;
    height: 80px;
    background-color: cyan;
  }

  .test-container {
    flex-direction: row;
    justify-content: space-between;
    margin-top: 10px;
  }

  .test-item {
    flex: 1;
    margin: 0 5px;
  }

  .test-box {
    width: 100%;
    height: 80px;
    background-color: gray;
  }

</style>

# 参见