2019独角兽企业重金招聘Python工程师标准>>> 
NSDATA-->NSDICTIONARY
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];NSDICTIONARY-->NSDATA
NSData *data = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];NSDATA-->NSSTRING
NSString *body = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];NSSTRING-->NSDATA
NSData *data = [strin dataUsingEncoding:NSUTF8StringEncoding];















