[iOS 개발] 사전(NSDictionary)과 JSON 문자열(NSString) 간 상호 회전

1. 사전에서 Json 문자열 바꾸기

+ (NSString*)convertToJSONData:(id)infoDict
{
    NSError *error;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:infoDict
                                                       options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
                                                         error:&error];

    NSString *jsonString = @"";

    if (! jsonData) 
    {
        NSLog(@"Got an error: %@", error);
    }else
    {
        jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    }

    jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];  // 

    [jsonString stringByReplacingOccurrencesOfString:@"
" withString:@""];

    return jsonString;
}

2. JSON 문자열이 사전으로 변환

+ (NSDictionary *)dictionaryWithJsonString:(NSString *)jsonString
{
    if (jsonString == nil) {
        return nil;
    }

    NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
    NSError *err;
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData
                                                        options:NSJSONReadingMutableContainers
                                                          error:&err];
    if(err)
    {
        NSLog(@"json ：%@",err);
        return nil;
    }
    return dic;
}