<view>
  <canvas style="width:663px;height:663px;" canvas-id="myCanvas"></canvas>
  <button data-event-opts="{{[['tap',[['go',['$event']]]]]}}" bindtap="__e">123</button>
</view>

go: function go() {
      var ctx = wx.createCanvasContext('myCanvas');

      // Create linear gradient
      var grd = ctx.createLinearGradient(0, 0, 200, 0);
      grd.addColorStop(0, 'red');
      grd.addColorStop(1, 'white');

      // Fill with gradient
      ctx.setFillStyle(grd);
      // ctx.fillRect(10, 10, 150, 80)
      ctx.fillText("职业", 5, 295);
      ctx.draw();

    }