会在一行上面显示黑色悬浮框、由于开发原因 需要修改宽度、找了好久。做下记录：
css

    <el-table
      :data="dataList"
      v-loading="listLoading"
      border
      fit
      highlight-current-row
      style="width: 100%;"
    >
      <el-table-column align="center" label="咨询的问题" show-overflow-tooltip>
        <template slot-scope="scope">
          <span>{{scope.row.askQuestions}}</span>
        </template>
      </el-table-column>
    </el-table>
<style lang="scss">
.el-tooltip__popper {
  max-width:30%
}
</style>