简体中文
简体中文
# flex-basis
flex-basis 属性设置弹性元素在主轴方向的初始大小，即在分配剩余空间（flex-grow）或收缩溢出空间（flex-shrink）的基准尺寸。当弹性元素同时设置了 flex-basis（除 auto 外的值）和 width（或 flex-direction 为 column 时设置了 height），flex-basis 的优先级更高。
# uni-app x 兼容性
| Web | Android | iOS | HarmonyOS | HarmonyOS(Vapor) |
|---|---|---|---|---|
| 4.0 | 3.9 | 4.11 | 4.61 | 5.0 |
# 语法
flex-basis: content | <'width'>;
# 值限制
- number
- length
- percentage
# flex-basis 的属性值
| 名称 | 兼容性 | 描述 |
|---|---|---|
| auto | 参照元素的 width 和 height 属性计算初始大小。 | |
| content | 基于 flex 的元素的内容自动调整大小。 **备注：**由于最初规范中没有包括这个值，在一些早期的浏览器实现的 flex 布局中，content 值无效，可以利用设置 (width 或 height) 为 auto 达到同样的效果。 备注： 简史 最初，"flex-basis:auto" 的含义是 "参照我的width和height属性". 在此之后，"flex-basis:auto" 的含义变成了自动尺寸，而 "main-size" 变成了 "参照我的width和height属性"。实际执行于 bug 1032922. 然后呢，这个更改又在 bug 1093316 中被撤销了，所以 "auto" 变回了原来的含义; 而一个新的关键字 'content' 变成了自动尺寸。 (Firefox bug 1105111 包括了增加这个关键字). |
# 默认值
auto
# 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
示例
<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-basis</text>
<view class="demo-box">
<view class="flex-container">
<view class="common" style="flex-basis: 100px">
<text>100px</text>
</view>
<view class="flex-item green"></view>
<view class="flex-item blue"></view>
</view>
<view class="flex-container">
<view class="common" style="flex-basis: 100px" flatten>
<text>100px</text>
</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">setProperty 设置与 getPropertyValue 获取 flex-basis </text>
</view>
<!-- 普通版本 -->
<view class="test-container">
<!-- view 组件测试 -->
<view class="test-item">
<text class="uni-subtitle-text">view 组件</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActual}}</text>
<view class="test-box">
<view class="test-flex-container">
<view class="common-image red"></view>
<view ref="viewRef" class="common-image green test-view" :style="{ flexBasis: flexBasis }">
<text class="test-label">view</text>
</view>
<view class="common-image blue"></view>
</view>
</view>
</view>
<!-- text 组件测试 -->
<view class="test-item">
<text class="uni-subtitle-text">text 组件</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActualText}}</text>
<view class="test-box">
<view class="test-flex-container">
<text class="common-text red">红色</text>
<text ref="textRef" class="common-text green test-text" :style="{ flexBasis: flexBasis }">text</text>
<text class="common-text blue">蓝色</text>
</view>
</view>
</view>
<!-- image 组件测试 -->
<view class="test-item">
<text class="uni-subtitle-text">image 组件</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActualImage}}</text>
<view class="test-box">
<view class="test-flex-container">
<image class="common-image red" src="/static/test-image/logo.png"></image>
<image ref="imageRef" class="common-image green test-image" :style="{ flexBasis: flexBasis }" src="/static/test-image/logo.png"></image>
<image class="common-image blue" src="/static/test-image/logo.png"></image>
</view>
</view>
</view>
</view>
<!-- 拍平版本 -->
<view class="test-container">
<!-- view 组件拍平测试 -->
<view class="test-item">
<text class="uni-subtitle-text">view 组件拍平</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActualFlat}}</text>
<view class="test-box">
<view class="test-flex-container">
<view class="common-image red"></view>
<view ref="viewRefFlat" class="common-image green test-view-flatten" :style="{ flexBasis: flexBasis }" flatten>
<text class="test-label">view</text>
</view>
<view class="common-image blue"></view>
</view>
</view>
</view>
<!-- text 组件拍平测试 -->
<view class="test-item">
<text class="uni-subtitle-text">text 组件拍平</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActualTextFlat}}</text>
<view class="test-box">
<view class="test-flex-container">
<text class="common-text red">红色</text>
<text ref="textRefFlat" class="common-text green test-text-flatten" :style="{ flexBasis: flexBasis }" flatten>text</text>
<text class="common-text blue">蓝色</text>
</view>
</view>
</view>
<!-- image 组件拍平测试 -->
<view class="test-item">
<text class="uni-subtitle-text">image 组件拍平</text>
<text class="uni-info">设置值: {{flexBasis}}</text>
<text class="uni-info">获取值: {{flexBasisActualImageFlat}}</text>
<view class="test-box">
<view class="test-flex-container">
<image class="common-image red" src="/static/test-image/logo.png"></image>
<image ref="imageRefFlat" class="common-image green test-image-flatten" :style="{ flexBasis: flexBasis }" flatten src="/static/test-image/logo.png"></image>
<image class="common-image blue" src="/static/test-image/logo.png"></image>
</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="flexBasisEnum" title="flex-basis 枚举值" @change="radioChangeFlexBasis" :compact="true"></enum-data>
<input-data :defaultValue="flexBasis" title="flex-basis 自定义值" type="text" @confirm="inputChangeFlexBasis"></input-data>
</view>
</view>
<!-- #ifdef APP -->
</scroll-view>
<!-- #endif -->
</template>
<script setup lang="uts">
import { ItemType } from '@/components/enum-data/enum-data-types'
const flexBasisEnum: ItemType[] = [
{ value: 0, name: '' },
{ value: 1, name: '0' },
{ value: 2, name: '0px' },
{ value: 3, name: '50px' },
{ value: 4, name: '0%' },
{ value: 5, name: '50%' },
{ value: 6, name: 'auto' },
]
const flexBasis = ref('30px')
const flexBasisActual = ref('')
const flexBasisActualFlat = ref('')
const flexBasisActualText = ref('')
const flexBasisActualImage = ref('')
const flexBasisActualTextFlat = ref('')
const flexBasisActualImageFlat = ref('')
const viewRef = ref(null as UniElement | null)
const viewRefFlat = ref(null as UniElement | null)
const textRef = ref(null as UniTextElement | null)
const imageRef = ref(null as UniImageElement | null)
const textRefFlat = ref(null as UniTextElement | null)
const imageRefFlat = ref(null as UniImageElement | null)
const getPropertyValues = () => {
flexBasisActual.value = viewRef.value?.style.getPropertyValue('flex-basis') ?? ''
flexBasisActualFlat.value = viewRefFlat.value?.style.getPropertyValue('flex-basis') ?? ''
flexBasisActualText.value = textRef.value?.style.getPropertyValue('flex-basis') ?? ''
flexBasisActualTextFlat.value = textRefFlat.value?.style.getPropertyValue('flex-basis') ?? ''
flexBasisActualImage.value = imageRef.value?.style.getPropertyValue('flex-basis') ?? ''
flexBasisActualImageFlat.value = imageRefFlat.value?.style.getPropertyValue('flex-basis') ?? ''
}
const changeFlexBasis = (value: string) => {
flexBasis.value = value
viewRef.value?.style.setProperty('flex-basis', value)
viewRefFlat.value?.style.setProperty('flex-basis', value)
textRef.value?.style.setProperty('flex-basis', value)
textRefFlat.value?.style.setProperty('flex-basis', value)
imageRef.value?.style.setProperty('flex-basis', value)
imageRefFlat.value?.style.setProperty('flex-basis', value)
// 使用 nextTick 确保样式已应用后再获取值
nextTick(() => {
getPropertyValues()
})
}
const radioChangeFlexBasis = (index: number) => {
const selectedItem = flexBasisEnum.find((item): boolean => item.value === index)
if (selectedItem != null) {
changeFlexBasis(selectedItem.name)
}
}
const inputChangeFlexBasis = (value: string) => {
changeFlexBasis(value)
}
onReady(() => {
getPropertyValues()
})
defineExpose({
radioChangeFlexBasis
})
</script>
<style>
.demo-box {
flex-direction: row;
margin-top: 10px;
justify-content: space-around;
}
.flex-container {
flex: 1;
margin: 0 10px;
height: 80px;
background-color: gray;
flex-direction: row;
}
.flex-item {
width: 40px;
height: 40px;
}
.red {
background-color: red;
}
.green {
background-color: green;
}
.blue {
background-color: blue;
}
.common {
width: 40px;
height: 40px;
background-color: red;
justify-content: center;
align-items: center;
}
.common-text {
width: 30px;
height: 30px;
font-size: 12px;
color: white;
}
.common-image {
width: 30px;
height: 30px;
}
.test-container {
flex-direction: row;
justify-content: space-between;
margin-top: 10px;
}
.test-item {
flex: 1;
margin: 0 5px;
}
.test-box {
width: 100%;
height: 50px;
background-color: gray;
}
.test-flex-container {
width: 100%;
height: 100%;
flex-direction: row;
}
.test-label {
font-size: 12px;
}
</style>
