class Model : NSObject{

    var details_url:String?
    var easy_time:String?
  }
 
    class func creatModel(dictionary :Dictionary<String, Any>) -> Model{
  
        let model = Model.init()
        model.setValuesForKeys(dictionary)
        
        return model
    }

    override func setValue(_ value: Any?, forUndefinedKey key: String) {
    }

      if (self.model?.details_url) != nil && (self.model?.details_url?.characters.count)! > 0
            {
            self.urlString = self.model?.details_url;
        }
        else if ( self.model?.easy_url ) != nil  && (self.model?.easy_url?.characters.count)! > 0
        {
            self.urlString = self.model?.easy_url;
        }
        else{
            NSLog("无效的 web url");
        }

self.navigationItem.backBarButtonItem = UIBarButtonItem.init(title: "", style:.plain, target: nil, action: nil)