try { |           
a = this.$refs.canvas.getContext("2d"), a.drawImage(this.$refs.main, 0, 0); |         } catch { |       
  } |    
     this.$nextTick(() => {

今天下载项目npm i 后 报错You may need an appropriate loader to handle this file typ，后面百度都没有发现错误在哪里，

最后安装了   ，解决了

npm i webpack-dev-server