<view>
   <text class="mi">expand_more</text>
   <text class="mi">expand_more</text>
   <text class="mi">expand_more</text>
</view>

let query = uni.createSelectorQuery().in(this)
      query.selectAll(`.mi`).boundingClientRect((res: any) => {
        res.forEach(item => {
          console.log(item.width)
        })
      })
      query.exec()

/* fallback */
@font-face {
  font-family: 'Material Icons';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/materialicons/v50/flUhRq6tzZclQEJ-Vdg-IuiaDsNc.woff2) format('woff2');
}

.mi {
  font-family: 'Material Icons';
  font-weight: normal;
  font-style: normal;
  font-size: 24px;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  display: inline-block;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-feature-settings: 'liga';
  -webkit-font-smoothing: antialiased;
}

或者

https://fonts.googleapis.com/icon?family=Material+Icons

但是 mi的类名要改成 material-icons