archivedDataWithRootObject NSUserDefaults

archivedDataWithRootObject  存储

BusinessCard *bc = [[BusinessCard alloc] init];  
NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];  
NSData *udObject = [NSKeyedArchiver archivedDataWithRootObject:bc];  
[ud setObject:udObject forKey:@"myBusinessCard"];  
   
udObject = nil;  
udObject = [ud objectForKey:@"myBusinessCard"];  
bc = [NSKeyedUnarchiver unarchiveObjectWithData:udObject] ;