iOS:JSON格式字符串转字典,字典转JSON格式字符串

+ (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解析失败：%@",err);                return nil;    }    return dic;}

+ (NSString*)dictionaryToJson:(NSDictionary *)dic{        NSError *parseError = nil;        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPRettyPrinted error:&parseError];        return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];    }