主要是公司对前端要求不高，能解决问题就行了，前端不太熟，用js这种处理起来方便，在此记录下。

在src中创建一个api目录，新建custom.js

export const getDivHeightByClass = (className) => {
    let divElements = document.getElementsByClassName(className);
    for (let i = 0; i < divElements.length; i++) {
        let height = divElements[i].offsetHeight;
        return height;
    }
    return 0;
};

export const getDivWidthByClass = (className) => {
    let divElements = document.getElementsByClassName(className);
    for (let i = 0; i < divElements.length; i++) {
        let height = divElements[i].offsetWidth;
        return height;
    }
    return 0;
};

在对应的vue中导入，然后就可以直接调用了

<template>
    ......
</template>

<script>
import {getDivHeightByClass, getDivWidthByClass} from '../../api/custom.js'
export default {
    ......
    ......
    mounted() {
        let height = getDivHeightByClass("xxx");
        let width = getDivWidthByClass("yyy");
    }
}
</script>