ios – NSURLConnection：JSON文本没有从数组或对象开始,并且选项允许未设置片段

“(Cocoa错误3840.)”(JSON文本没有从数组或对象开始,并且选项允许片段未设置.)UserInfo = 0x7b71dbb0 {NSDebugDescription = JSON文本没有以数组或对象开头并允许片段未设置的选项.

我使用以下代码：

-(void)connectionDidFinishLoading:(NSURLConnection *)connection 
{
    NSError *error;
    id json = [NSJSONserialization JSONObjectWithData:_urlData options:kNilOptions error:&error];

    if (error) {
        NSLog(@"Loading Error = %@",error);
    }
}

以下是我的json回复：

{  
   "result":"success","details":[  
      {  
         "id":"11531","user_name":"","fullname":"aa","email_address":"aa","user_type":"a","server":"","server_email":"","server_password":"","password":"0cc175b9c0f1b6a831c399e269@R_489_11327@661","clean_password":"a","gender":"","ceo_name":"","ceo_picture":"","ceo_contact":"","ceo_contact_pic":"","company_name":"a","freight_company_name":"","freight_company_email":"","company_url":"11531","company_keyword":"","company_description":"","address":"","province":"","postal_code":"","phone_number":"","fax_number":"","website":"","city":"","b_category":"","main_products":"","cellphone":"a","country":"0","states":"","company_status":"1","joindate":"0","varificationcode":"","activation_status":"1","new_email":"","email_activation_status":"","facebook_url":"","twitter_url":"","company_update_status":"0","last_access_date":"0000-00-00","ip_address":"","ip_block":"0","user_id":null,"company_id":null,"video_url":"","oauth_uid":"","oauth_provider":"","get_color":"","comp_name_size":"13","member_type":"","mark_status":"1","ip_address_intension":"","fbId":"","twitterId":"","profile_picture":"","device_token":""
      }
   ]
}

我已经尝试了stackOverflow中的所有解决方案,但是静态.