flutter复制文件

/*
  * 复制文件
  * file需要复制的文件
  * storedPath复制的文件的存放路径
  * */
  copyFile(List<File> fileList) async {
    List<String> draftsFilePathList = [];
    Completer<List<String>> _completer = Completer<List<String>>();
    Directory libDir = await getExternalStorageDirectory();
    String draftsPath = libDir.path + '/draftsFiles';
    var directory = Directory(draftsPath);
    try{
      bool exists = await directory.exists();
      if(!exists){
        await directory.create();
      }
    }catch(e){
      print(e.toString());
    }
    if(fileList.length > 0){
      for (int i = 0; i < fileList.length; i++) {
        try{
          String imageSuffix = '.'+fileList[i].path.substring(fileList[i].path.lastIndexOf(".") + 1, fileList[i].path.length);
          final newFile = await fileList[i].copy(draftsPath+'/drafts${getRandom(16)}$imageSuffix');
          draftsFilePathList.add(newFile.path);
        }catch(e){
          print(e.toString());
        }
      }
    }
    _completer.complete(draftsFilePathList);
    return _completer.future;
  }