例如:
1、NSData轉字典
NSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
NSDictionary *myDictionary = [[unarchiver decodeObjectForKey:@"Some Key Value"]];
[unarchiver finishDecoding];
2、字典轉Json
NSString *jsonStr=[myDictionary JSONRepresentation];