iOS 对象数组生成jsonarray

//1. 初始化可变字符串，存放最终生成json字串  
        NSMutableString *jsonString = [[NSMutableString alloc] initWithString:@"{"actorhalls":["];  
          
        for(ExecplanActosHall *hall in actorhalls){  
              
            //2. 遍历数组，取出键值对并按json格式存放  
            NSString *string;  
              
            string  = [NSString stringWithFormat:  
                      @"{"ownerName":"%@","ownerId":"%@","channelId":"%@","ownerType":"%ld"},",hall.ownerName,hall.ownerId,hall.channelId,(long)hall.ownerType];  
              
            [jsonString appendString:string];  
              
        }  
        // 3. 获取末尾逗号所在位置  
        NSUInteger location = [jsonString length]-1;  
       
        NSRange range       = NSMakeRange(location, 1);  
          
        // 4. 将末尾逗号换成结束的]}  
        [jsonString replaceCharactersInRange:range withString:@"]}"];  
  
        NSLog(@"jsonString = %@",jsonString);  

 其一：字典转json

//字典转Json  
- (NSString*)dictionaryToJson:(NSDictionary *)dic  
{  
    NSError *parseError = nil;  
    NSData  *jsonData = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:&parseError];  
    return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];  
}  

其二：json转字典

/*!  
 * @brief 把格式化的JSON格式的字符串转换成字典  
 * @param jsonString JSON格式的字符串  
 * @return 返回字典  
 */  
+ (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;  
}