bwj_wechat/pages/tabbar-pages/home/analysis/painter/painter.wxml

<view style='position: relative;{{customStyle}};{{painterStyle}}'>
  <canvas canvas-id="photo" style="{{photoStyle}};position: absolute; left: -9999px; top: -9999rpx;" />
  <canvas canvas-id="bottom" style="{{painterStyle}};position: absolute;" />
  <canvas canvas-id="k-canvas" style="{{painterStyle}};position: absolute;" />
  <canvas canvas-id="top" style="{{painterStyle}};position: absolute;" />
  <canvas 
    canvas-id="front" 
    style="{{painterStyle}};position: absolute;"
    bindtouchstart="onTouchStart"
    bindtouchmove="onTouchMove"
    bindtouchend="onTouchEnd"
    bindtouchcancel="onTouchCancel"
    disable-scroll="{{true}}" />
</view>