How can I convert NSDictionary to NSData and vice versa?

Question

I am sending NSString and UIImage using bluetooth. I decided to store both in a NSDictionary and then convert the dictionary to

Answer 1

NSDictionary -> NSData:

NSData *myData = [NSKeyedArchiver archivedDataWithRootObject:myDictionary];

NSData -> NSDictionary:

NSDictionary *myDictionary = (NSDictionary*) [NSKeyedUnarchiver unarchiveObjectWithData:myData];