ios - 第一次点击显示不出来必需返回再点击才可以出数据？而且滞后？

  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
   var DestViewController = segue.destinationViewController as! AirViewController
        let headers2 = [
            "Accept":"application/json",
            "X-User-Phone": "18516591232",
            "X-User-Token": "CL-QVwfSZSUAcsEVFscc"
        ]
        
        let body = [
            "sub_sys_name":"空调系统"
        ]
        
        Alamofire.request(.POST, "http://139.196.190.201/rooms/1/devices/search", headers: headers2, parameters: body)
            .responseString { response in
                let json = JSON(data: response.data!)
                var peidians_detail = json["devices"]
                var arry = peidians_detail.count
                
                Airid = []
                Airname = []
                for (name1, value1) in peidians_detail {
                    Airid.append(value1["id"].stringValue)
                    Airname.append(value1["name"].stringValue)
                }
        }
        DestViewController.navigationItem.title = "空调系统"
    }
 ｝

在另一个tableview读取数组count

    
 override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return Airname.count
}