index.wxml

<view class="vchart" id="{{ canvasId }}" style="{{ styles }}">
  <canvas
    class="cs-canvas"
    bindtouchstart="bindEvent"
    bindtouchmove="bindEvent"
    bindtouchend="bindEvent"
    bindmousemove="bindEvent"
    bindmouseover="bindEvent"
    bindmouseout="bindEvent"
    bindmousedown="bindEvent"
    bindmouseup="bindEvent"
    id="{{ canvasId }}_draw_canvas"
    canvas-id="{{ canvasId }}_draw_canvas"
    type="2d"
  ></canvas>
  <canvas width="{{ offscreenCanvasWidth }}" height="{{ offscreenCanvasHeight }}" id="{{ canvasId }}_hit_canvas"
    canvas-id="{{ canvasId }}_hit_canvas" class="cs-tooltip-canvas" type="2d"></canvas>
  <canvas width="{{ offscreenCanvasWidth }}" height="{{ offscreenCanvasHeight }}" id="{{ canvasId }}_tooltip_canvas"
    canvas-id="{{ canvasId }}_tooltip_canvas" class="cs-tooltip-canvas" type="2d"></canvas>
</view>