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Flex Direction

docs/css/flex-direction.md

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flex-direction

flex-direction 属性设置弹性容器中的子元素的布局方向，该方向定义为主轴，另一个垂直与它的方向为交叉轴。

uni-app x 兼容性

WebAndroidiOSHarmonyOSHarmonyOS(Vapor)
4.03.94.114.615.0

语法

flex-direction: row | row-reverse | column | column-reverse;

值限制

  • enum

flex-direction 的属性值

名称兼容性描述
rowWeb: 4.0; Android: 3.9; iOS: 4.11; HarmonyOS: 4.61; HarmonyOS(Vapor): 5.0flex 容器的主轴被定义为与文本方向相同。主轴起点和主轴终点与内容方向相同。
row-reverseWeb: 4.0; Android: 3.9; iOS: 4.11; HarmonyOS: 4.61; HarmonyOS(Vapor): 5.0表现和 row 相同，但是置换了主轴起点和主轴终点
columnWeb: 4.0; Android: 3.9; iOS: 4.11; HarmonyOS: 4.61; HarmonyOS(Vapor): 5.0flex 容器的主轴和块轴相同。主轴起点与主轴终点和书写模式的前后点相同
column-reverseWeb: 4.0; Android: 3.9; iOS: 4.11; HarmonyOS: 4.61; HarmonyOS(Vapor): 5.0表现和column相同，但是置换了主轴起点和主轴终点

默认值 @default-value

平台默认值
uvuecolumn

注意：W3C 默认值为：row

适用组件 @unix-tags

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 ::: preview https://hellouniappx.dcloud.net.cn/web/#/pages/CSS/flex/flex-direction

appRedirect https://hellouniappx.dcloud.net.cn/appredirect.html?path=pages/CSS/flex/flex-direction

示例

vue
<template>
  <!-- #ifdef APP -->
  <scroll-view style="flex: 1">
  <!-- #endif -->
    <view style="flex-grow: 1">
      <text class="uni-tips">说明：左边是正常版本，右边是拍平版本</text>
      <view>
        <text>flex-direction: row</text>
        <view class="demo-box">
          <view class="common" style="flex-direction: row">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
          <view class="common" style="flex-direction: row" flatten>
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
        </view>
      </view>

      <view>
        <text>flex-direction: row-reverse</text>
        <view class="demo-box">
          <view class="common" style="flex-direction: row-reverse">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
          <view class="common" style="flex-direction: row-reverse" flatten>
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
        </view>
      </view>

      <view>
        <text>flex-direction: column</text>
        <view class="demo-box">
          <view class="common" style="flex-direction: column">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
          <view class="common" style="flex-direction: column" flatten>
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
        </view>
      </view>

      <view>
        <text>flex-direction: column-reverse</text>
        <view class="demo-box">
          <view class="common" style="flex-direction: column-reverse">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
          <view class="common" style="flex-direction: column-reverse" flatten>
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </view>
        </view>
      </view>

      <view class="uni-common-mt">
        <text class="uni-title-text">scroll-view 组件</text>
      </view>

      <view>
        <text class="uni-subtitle-text">flex-direction：row 和 column</text>
        <view class="demo-box">
          <scroll-view class="common" style="flex-direction: row;" direction="horizontal">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </scroll-view>
          <scroll-view class="common" style="flex-direction: column;" direction="horizontal">
            <view class="flex-item red"></view>
            <view class="flex-item green"></view>
            <view class="flex-item blue"></view>
          </scroll-view>
        </view>
      </view>

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

      <view class="common-box">
        <!-- 普通版本 -->
        <view class="uni-common-mt">
          <text class="uni-title-text">flex-direction</text>
          <text class="uni-info">设置值: {{flexDirection}}</text>
          <text class="uni-info">获取值: {{flexDirectionActual}}</text>
          <view class="test-box">
            <view ref="viewRef" class="test-flex-container test-view" :style="{ flexDirection: flexDirection }">
              <view class="test-item-small red"></view>
              <view class="test-item-small green"></view>
              <view class="test-item-small blue"></view>
            </view>
          </view>
        </view>

        <!-- 拍平版本 -->
        <view class="uni-common-mt">
          <text class="uni-title-text">拍平</text>
          <text class="uni-info">设置值: {{flexDirection}}</text>
          <text class="uni-info">获取值: {{flexDirectionActualFlat}}</text>
          <view class="test-box">
            <view ref="viewRefFlat" class="test-flex-container test-view-flatten" :style="{ flexDirection: flexDirection }" flatten>
              <view class="test-item-small red"></view>
              <view class="test-item-small green"></view>
              <view class="test-item-small blue"></view>
            </view>
          </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="flexDirectionEnum" title="flex-direction 枚举值" @change="radioChangeFlexDirection" :compact="true"></enum-data>
        <input-data :defaultValue="flexDirection" title="flex-direction 自定义值" type="text" @confirm="inputChangeFlexDirection"></input-data>
      </view>
    </view>
  <!-- #ifdef APP -->
  </scroll-view>
  <!-- #endif -->
</template>

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

  const flexDirectionEnum: ItemType[] = [
    { value: 0, name: '' },
    { value: 1, name: 'row' },
    { value: 2, name: 'row-reverse' },
    { value: 3, name: 'column' },
    { value: 4, name: 'column-reverse' }
  ]

  const flexDirection = ref('row')
  const flexDirectionActual = ref('')
  const flexDirectionActualFlat = ref('')
  const viewRef = ref(null as UniElement | null)
  const viewRefFlat = ref(null as UniElement | null)

  const getPropertyValues = () => {
    flexDirectionActual.value = viewRef.value?.style.getPropertyValue('flex-direction') ?? ''
    flexDirectionActualFlat.value = viewRefFlat.value?.style.getPropertyValue('flex-direction') ?? ''
  }

  const changeFlexDirection = (value: string) => {
    flexDirection.value = value
    viewRef.value?.style.setProperty('flex-direction', value)
    viewRefFlat.value?.style.setProperty('flex-direction', value)
    // 使用 nextTick 确保样式已应用后再获取值
    nextTick(() => {
      getPropertyValues()
    })
  }

  const radioChangeFlexDirection = (index: number) => {
    const selectedItem = flexDirectionEnum.find((item): boolean => item.value === index)
    if (selectedItem != null) {
      changeFlexDirection(selectedItem.name)
    }
  }

  const inputChangeFlexDirection = (value: string) => {
    changeFlexDirection(value)
  }

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

  defineExpose({
    radioChangeFlexDirection
  })
</script>

<style>
  .demo-box {
    flex-direction: row;
    margin-top: 10px;
    justify-content: space-around;
  }

  .flex-item {
    width: 40px;
    height: 40px;
  }
  .red {
    background-color: red;
  }
  .green {
    background-color: green;
  }
  .blue {
    background-color: blue;
  }
  .common {
    flex: 1;
    margin: 0 10px;
    height: 220px;
    background-color: gray;
  }
  .common-box{
    flex-direction: row;
    justify-content: space-around;
  }

  .test-box {
    width: 180px;
    height: 150px;
    background-color: gray;
  }


  .test-flex-container {
    width: 100%;
    height: 100%;
    background-color: gray;
  }

  .test-item-small {
    width: 30px;
    height: 30px;
  }
</style>

:::

参见