如何查看HarmonyOS下载文件

import picker from '@ohos.file.picker'; 
let context = getContext(this) as common.UIAbilityContext; 
let fileDir = context.cacheDir; 
let rawFile = value; 
const documentSaveOptions = new picker.DocumentSaveOptions(); 
let savedFileName = new Date().getTime() + '.png'; 
documentSaveOptions.newFileNames = [savedFileName]; 
const documentViewPicker = new picker.DocumentViewPicker(); 
documentViewPicker.save(documentSaveOptions).then((documentSaveResult)=>{ 
  if (documentSaveResult !== null && documentSaveResult !== undefined) { 
    console.log('documentViewPicker.save to file succeed and uris are:' + documentSaveResult[0]); 
    let newFile = fs.openSync(documentSaveResult[0], fs.OpenMode.READ_WRITE); 
    let writeLen = fs.writeSync(newFile.fd, rawFile.buffer); 
    console.log('write data to file success and size is:' + writeLen); 
  } 
}).catch((err:BusinessError)=>{ 
  console.log(`Invoke documentViewPicker.save to file failed, code is ${err.code}, message is ${err.message}`) 
})