vue3+el-select实现触底加载更多功能(ts版)

思路

使用全局指令来实现触底加载功能

通过el-select中的popper-class给下拉框加入一个类名

在src下的utils文件夹中创建selectLoadMoreDirective.ts文件

import { Directive, DirectiveBinding } from \’vue\’
const loadMore: Directive = {
beforeMount(el: any, binding: DirectiveBinding) {
console.log(el)
const selectDom = (document.querySelector(\”.more_select_dropdown\”) as any).querySelector(\”.el-select-dropdown .el-select-dropdown__wrap\”);
console.log(selectDom, \’selectDom++++++++++++++\’);
function loadMores(this: any) {
const isBase = this.scrollHeight – this.scrollTop <= this.clientHeight
if (isBase) {
binding.value && binding.value()
}
}
el.selectDomInfo = selectDom
el.userLoadMore = loadMores
nextTick(() => {
selectDom?.addEventListener(\’scroll\’, loadMores)
})
},
beforeUnmount(el: any) {
if (el.userLoadMore) {
el.selectDomInfo.removeEventListener(\’scroll\’, el.userLoadMore)
delete el.selectDomInfo
delete el.userLoadMore
}
}
}
export default loadMore

main.ts

import { createApp } from \’vue\’
import App from \’./App.vue\’
import router from \’/@/router\’
import loadMore from \’@/utils/selectLoadMoreDirective\’
const app = createApp(App)
app.use(router)
app.directive(\’loadMore\’, loadMore)

home.vue

<template>
<div class=\”p-2\”>
<el-select v-model=\”selectedValue\” v-loadMore=\”loadMore\” class=\”more-select\” popper-class=\”more_select_dropdown\”
@change=\”selectChange\”>
<el-option v-for=\”(item, index) in list\” :key=\”`${item.value}${index}`\” :label=\”item.label\” :value=\”item.value\” />
</el-select>
</div>
</template>
<script setup name=\”Home\” lang=\”ts\”>
import { ComponentInternalInstance, computed, getCurrentInstance, nextTick, onMounted, reactive, ref, toRefs } from \’vue\’;
const selectedValue = ref([])
const selectData = reactive({
pageIndex: 1,
pageSize: 5,
finished: false
})
const list = ref([
{
value: 1,
label: \’测试1\’
},
{
value: 2,
label: \’测试2\’
},
{
value: 3,
label: \’测试3\’
},
{
value: 4,
label: \’测试4\’
},
{
value: 5,
label: \’测试5\’
},
{
value: 6,
label: \’测试6\’
},
{
value: 7,
label: \’测试7\’
},
{
value: 8,
label: \’测试8\’
},
])
//触底函数
const loadMore = () => {
console.log(\’ 触底了\’);
// 防抖处理
setTimeout(() => {
if (selectData.finished) return //值为true，则代表没有数据了
selectData.pageIndex += 1
// list.value = list.value.concat(list2.value)
for (let i = 1; i <= 8; i++) {
list.value.push({
value: i,
label: `测试${i}`
})
}
}, 500)
}
//选中值发生变化时触发
const selectChange = () => {
console.log(\’选中的xxxx\’)
}
</script>