el-table怎么获取指定元素的宽度？

<el-table :data="tableData" style="width:100%">
          <el-table-column  prop="username" label="用户姓名" width="150">el-table-column>
          <el-table-column  prop="userid" label="用户编号" width="120">el-table-column>
          <el-table-column  prop="opreateType" label="操作类型" width="120">el-table-column>
          <el-table-column  prop="opreateDetail" label="操作详情" ref="opreateDetail">
            <template slot-scope="scope">
              <el-tooltip :content="scope.row.opreateDetail" placement="top">
                <div class="spread-box" :style="{'-webkit-line-clamp':scope.row.spread ? '':3}">
                  {{scope.row.opreateDetail}}
                div>
              el-tooltip>
              <div v-show="scope.row.spread==false" @click="spreadText(scope.row)" class="spread-btn">
                <el-button type="text">展开<el-icon class="el-icon-arrow-down">el-icon>el-button>
              div>
              <div v-show="scope.row.spread==true" @click="spreadText(scope.row)" class="spread-btn">
                <el-button type="text">收起<el-icon class="el-icon-arrow-up">el-icon>el-button>
              div>
            template>  
          el-table-column>
          <el-table-column prop="createTime" :formatter="formatter" label="修改时间" width="220">el-table-column>
        el-table>

mounted(){
console.log(this.$refs.opreateDetail.$el.offsetWidth)
}

如上,想获取操作详情这一列元素的宽度，然后再设置el-tooltip的宽度=该宽度.但是this.$refs.opreateDetail.$el.offsetWidth打印出来是0？

帮你找了个相似的问题, 你可以看下: https://ask.csdn.net/questions/7521641
你也可以参考下这篇文章：el-table表头自适应宽度(解决出现省略号的问题)

你说的这种没实验过不敢乱说，但是你可以直接给个百分比，这样就不会出现问题了，比如

<style lang="scss">
    .el-tooltip__popper {
        max-width: 60%;
    }
</style>