wx.serviceMarket.invokeService({

      service: 'wx79ac3de8be320b71', // '固定为服务商OCR的appid，非小程序appid',

      api: 'OcrAllInOne',

      data: {

        //img_url: imgPath,

img_url: new wx.serviceMarket.CDN({

    type: 'filePath',

    filePath: imgPath

}),

        data_type: 3,