aliapp-demo/page/API/canvas/example.axml

<view class="page">
  <view class="page__hd">
    <text class="page__title">{{method}}</text>
    <text class="page__desc">{{introduction}}</text>
  </view>
  <view class="page__bd">
    <view class="section section_gap">
      <canvas style="width: 100%; height: 300px;" id="mycanvas"></canvas>
    </view>
  </view>
</view>