实现Element Select选择器滚动加载

<template><el-selectpopper-class="more-tag-data"v-model="tagId"filterableplaceholder="请选择"@focus="focusTag"><el-optionv-for="(item, index) in taskTagLists":key="index":label="item.name":value="item.id"></el-option></el-select>
</template><script>
export default {data() {return {tagPage: {pageSize: 10,currentPage: 1,total: 0},taskTagLists: []}},created() {getTmpList({pageNum: this.tagPage.currentPage,pageSize: this.tagPage.pageSize}).then(res => {this.tagPage.total = res.data.totalthis.taskTagLists = res.data.list})},methods: {focusTag() {// 获取dom节点const domElementNode = document.querySelector('.more-tag-data .el-select-dropdown__wrap')// 注册下拉滚动事件domElementNode.addEventListener('scroll',  ()=>{const isBottom = domElementNode.scrollHeight - domElementNode.scrollTop <= domElementNode.clientHeightif (isBottom) {this.loadMore()}})},loadMore() {if(this.tagPage.currentPage * this.tagPage.pageSize < this.tagPage.total) {this.tagPage.currentPage ++this.getTageValue()}},getTageValue() {getTmpList({pageNum: this.tagPage.currentPage,pageSize: this.tagPage.pageSize}).then(res => {this.taskTagLists = this.taskTagLists.concat(res.data.list)})}}
}
</script>

注意：

        因为select组件在默认情况下是display:none的状态，所以不能把监听滚动事件放到mounted内，会获取不到元素class。