swift 闭包

         let me = { (a:int,b:int) -> int in 

          return a + b
  
        }

        me(2,3)

========

  override func viewDidLoad() {
        
        super.viewDidLoad()

     let para =  ["a":"3","b":"4"]  as [String : AnyObject]
        NetworkTool.bbb( url:"http://wweqweqw",   parameters : para ){ (topTitles) in

            print(topTitles)

        }
    
    }
========

class NetworkTool: NetworkToolProtocol {
    
  //test
    class func bbb(  url:String,   parameters : [String : AnyObject], completionHandler:@escaping (_ topTitles: Any?)->()) {
        
        print(parameters)
        
        Alamofire.request(url, parameters: parameters).responseJSON { (response) in
        
                
            guard response.result.isSuccess else {
                return
            }
            
            
            if let value = response.result.value {
                let json = JSON(value)
               
                    completionHandler(json)
            }
        
        }
        

    }    



}