<canvas style="width: {{posterBoxWidth}}px;height: {{posterBoxHeight}}px;position:fixed;top:9999px;background-color:white" canvas-id="mycanvas" />

<canvas style="width: {{posterBoxWidth2}}px;height: {{posterBoxHeight2}}px;position:fixed;top:9999px;background-color:white" canvas-id="mycanvas2" />

是还没开始画东西 页面上下滚动会有卡顿