前言

最近主管提出了许多优化用户体验的要求，其中很多涉及 dom 操作。本文将 Vue3 中常见的 dom 操作总结了一下。觉得文章不错、或对自己开发有所帮助，欢迎点赞收藏！

一、通过 ref 拿到 dom 的引用

<template>
    <div class="ref-container">
        <div ref="sectionRef" class="ref-section"></div>
    </div>
</template>
<script lang="ts" setup>
import { ref } from 'vue'
const sectionRef = ref()
</script>

通过对 div 元素添加 ref 属性，为了获取到这个元素，我们声明了一个与 ref 属性名称相同的变量，然后通过 [变量名].value 的形式即可获取该 div 元素。

适用场景

• 单一 dom 元素或者个数较少的场景

示例代码

<template>
    <div class="ref-container">
        <p>通过 ref 直接拿到 dom</p>
        <div ref="sectionRef" class="ref-section"></div>
        <button @click="action" class="btn">变高</button>
    </div>
</template>
<script lang="ts" setup>
import { ref } from 'vue'
const sectionRef = ref()
let height = 100;
const action= () => {
    height += 50;
    sectionRef.value.style = `height: ${height}px`;
}
</script>
<style lang="scss" scoped>
.demo1-container {
    width: 100%;
    height: 100%;
    .ref-section {
        width: 200px;
        height: 100px;
        background-color: pink;
        transition: all .5s ease-in-out;
    }
    .btn {
        width: 200px;
        height: 50px;
        background-color: gray;
        color: #fff;
        margin-top: 100px;
    }
}
</style>

二、通过父容器的 ref 遍历拿到 dom 引用

通过对父元素添加 ref 属性，并声明一个与 ref 属性名称相同的变量 list，此时通过 list.value 会获得包含子元素的 dom 对象。此时可以通过 list.value.children[index] 的形式获取子元素 dom。

<template>
    <div class="ref-container">
        <div ref="list" class="list-section">
            <div @click="higherAction(index)" class="list-item" v-for="(item, index) in state.list" :key="index">
                <span>{{item}}</span>
            </div>
        </div>
    </div>
</template>
<script lang="ts" setup>
import { ref, reactive } from 'vue'
const list = ref()

适用场景

• 通过 v-for 循环生成的固定数量元素的场景。

示例代码

<template>
    <div class="ref-container">
        <p>通过父容器遍历拿到dom</p>
        <div ref="list" class="list-section">
            <div @click="higherAction(index)" class="list-item" v-for="(item, index) in state.list" :key="index">
                <span>{{item}}</span>
            </div>
        </div>
    </div>
</template>
<script lang="ts" setup>
import { ref, reactive } from 'vue'
const list = ref()
const state = reactive({
    list: [1, 2, 3, 4, 5, 6, 7, 8]
})
const higherAction = (index: number) => {
    let height = listRef.value.children[index].style.height ? listRef.value.children[index].style.height : '20px';
    height = Number(height.replace('px', ''));
    listRef.value.children[index].style = `height: ${height + 20}px`;
}
</script>
<style lang="scss" scoped>
.demo2-container {
    width: 100%;
    height: 100%;
    .list-section {
        width: 200px;
        .list-item {
            width: 200px;
            height: 20px;
            background-color: pink;
            color: #333;
            transition: all .5s ease-in-out;
            display: flex;
            justify-content: center;
            align-items: center;
        }
    }
}
</style>

三、通过子组件 emit 传递 ref

通过对子组件添加 ref 属性，并声明一个与 ref 属性名称相同的变量 childRef，此时通过 emit 将 childRef.value 作为一个 dom 引用传递出去。

<template>
    <div ref="childRef" @click="cellAction" class="cell-item">
        <span>{{item}}</span>
    </div>
</template>
<script lang="ts" setup>
import { ref } from 'vue'
const props = defineProps({
    item: Number
})
const emit = defineEmits(['cellTap']);
const childRef = ref();
const cellAction = () => {
    emit('cellTap', childRef.value);
}
</script>

适用场景

• 多个页面都可能有操作组件 dom 的场景

示例代码

<template>
    <div ref="childRef" @click="cellAction" class="cell-item">
        <span>{{item}}</span>
    </div>
</template>
<script lang="ts" setup>
import { ref } from 'vue'
const props = defineProps({
    item: Number
})
const emit = defineEmits(['cellTap']);
const childRef = ref()
const cellAction = () => {
    emit('cellTap', childRef.value);
}
</script>
<style lang="scss" scoped>
.cell-item {
    width: 200px;
    height: 20px;
    background-color: pink;
    color: #333;
    transition: all .5s ease-in-out;
    display: flex;
    justify-content: center;
    align-items: center;
}
</style>

<template>
    <div class="ref-container">
        <p>通过子组件emit传递ref</p>
        <div class="list-section">
            <Cell :item="item" @cellTap="cellTapHandler" v-for="(item, index) in state.list" :key="index">
            </Cell>
        </div>
    </div>
</template>
<script lang="ts" setup>
import { reactive } from 'vue'
import Cell from '@/components/Cell.vue'
const state = reactive({
    list: [1, 2, 3, 4, 5, 6, 7],
    refList: [] as Array<any>
})
const cellTapHandler = (el: any) => {
    let height = el.style.height ? el.style.height : '20px';
    height = Number(height.replace('px', ''));
    el.style = `height: ${height + 20}px`;
}
</script>
<style lang="scss" scoped>
.demo2-container {
    width: 100%;
    height: 100%;
    .list-section {
        width: 200px;
    }
}
</style>

四、通过 :ref 将 dom 引用放到数组中

通过 :ref 循环调用 setRefAction 方法，该方法会默认接收一个 el 参数，这个参数就是我们需要获取的 div 元素。

<template>
    <div class="ref-container">
        <div class="list-section">
            <div :ref="setRefAction" @click="higherAction(index)" class="list-item" v-for="(item, index) in state.list" :key="index">
                <span>{{item}}</span>
            </div>
        </div>
    </div>
</template>
<script lang="ts" setup>
import { reactive } from 'vue'
const state = reactive({
    list: [1, 2, 3, 4, 5, 6, 7],
    refList: [] as Array<any>
})
const setRefAction = (el: any) => {
    state.refList.push(el);
}
</script>

此时可以通过 state.refList[index] 的形式获取子元素 dom。

适用场景

• 通过 v-for 循环生成的不固定数量或者多种元素的场景。

示例代码

<template>
    <div class="ref-container">
        <p>通过:ref将dom引用放到数组中</p>
        <div class="list-section">
            <div :ref="setRefAction" @click="higherAction(index)" class="list-item" v-for="(item, index) in state.list" :key="index">
                <span>{{item}}</span>
            </div>
        </div>
    </div>
</template>
<script lang="ts" setup>
import { reactive } from 'vue'
const state = reactive({
    list: [1, 2, 3, 4, 5, 6, 7],
    refList: [] as Array<any>
})
const higherAction = (index: number) => {
    let height = state.refList[index].style.height ? state.refList[index].style.height : '20px';
    height = Number(height.replace('px', ''));
    state.refList[index].style = `height: ${height + 20}px`;
    console.log(state.refList[index]);
}
const setRefAction = (el: any) => {
    state.refList.push(el);
}
</script>
<style lang="scss" scoped>
.demo2-container {
    width: 100%;
    height: 100%;
    .list-section {
        width: 200px;
        .list-item {
            width: 200px;
            height: 20px;
            background-color: pink;
            color: #333;
            transition: all .5s ease-in-out;
            display: flex;
            justify-content: center;
            align-items: center;
        }
    }
}
</style>

总结

经过了不断探索终于完成了，事后想了一下还是自己的本事不到家，以后还是需要不断提升自己的能力 ~ ~ ~