使用imageSource如何存储图片

import { BusinessError } from '@kit.BasicServicesKit';
import { fileIo } from '@kit.CoreFileKit';
const context : Context = getContext(this);
const filePath : string = context.cacheDir + "/image_source.jpg";
let file = fileIo.openSync(filePath, fileIo.OpenMode.CREATE | fileIo.OpenMode.READ_WRITE);
imagePackerApi.packToFile(imageSource, file.fd, packOpts).then(() => {
直接打包进文件
}).catch((error : BusinessError) => { 
  console.error('Failed to pack the image. And the error is: ' + error); 
})