HarmonyOS 项目内代码如何获取项目的目录？

rawfile目录没有对外暴露的沙箱路径，需要先将文件拷贝进应用沙箱下再操作，拷贝进沙箱参考demo：

getContext(this).resourceManager.getRawFileContent('test.txt', (_err, value) => {
  let myBuffer: ArrayBufferLike = value.buffer
  let context = getContext(this);
  //沙箱路径 
  let filePath = context.filesDir + "/test.txt";
  console.log("testTag-filePath:" + filePath);
  let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
  let writeLen = fs.writeSync(file.fd, myBuffer);
  console.info("testTag-write data to file succeed and size is:" + writeLen);
  fs.closeSync(file);
})