ios - iOS 持久性：在目录中存储和检索项目

Question

我想将文件保存到文件夹，然后检索该文件夹的所有内容，所以我这样做：

NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:storageFolder];
// StorageFolder is just a string like: "@"/FavoritesFolder"
// Filename is just a title given like "myTune.mp3"        
NSString *destinationString = [NSString stringWithFormat:@"%@/%@",dataPath,filename];
  BOOL success = [object writeToFile:destinationString atomically:YES];

然后我想检索对象，所以我这样做

NSArray *dirContents = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:dataPath error:nil];

但我得到的只是一个数组filename（比如 myTune.mp3）。不是Object哪个是 NSDictionary。我究竟做错了什么？

Answer 1

You aren't strictly 'doing' anything wrong. It's your expectations that are wrong. The method you're using (contentsOfDirectoryAtPath:)

Performs a shallow search of the specified directory and returns the paths of any contained items.

If you want to load the file back into memory you need to:

1. Decide which file you want
2. Get the full path to the file (directory path and file name)
3. Load the file (if it's a dictionary, dictionaryWithContentsOfFile:)