通过packing方法将图片数据处理成jpg问题

const imagePackerApi : image.ImagePacker = image.createImagePacker(); 
const imageSourceApi : image.ImageSource = image.createImageSource(buffer); 
let packOpts : image.PackingOption = { format:“image/jpeg”, quality:98 } 
imagePackerApi.packing(imageSourceApi, packOpts) 
  .then( (data : ArrayBuffer) => { 
console.log(‘packing succeeded.’); 
let filePath = (this._context as Context).filesDir + ‘/data2.jpg’ 
let copyFile = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); 
fs.writeSync(copyFile.fd, data); 
fs.closeSync(copyFile) 
}).catch((error : BusinessError) => { 
  console.error(‘packing failed.’); 
})