如何在Swift中添加双击手势识别器

我已经完成了单击识别器,但无法弄清楚如何将该单击识别器改为双击.我可以使用一些指导.

码：

import Foundation
import UIKit

class MainBoardController: UIViewController{

    let tap = UITapGestureRecognizer()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view,typically from a nib.
        var swipe: UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self,action: "GotoProfile")
        swipe.direction = UISwipeGestureRecognizerDirection.Right
                    self.view.addGestureRecognizer(swipe)

        tap.addTarget(self,action: "GotoCamera")
        view.userInteractionEnabled = true
        view.addGestureRecognizer(tap)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // dispose of any resources that can be recreated.
    }

    func GotoProfile(){
        self.performSegueWithIdentifier("Profilesegue",sender: nil)
    }

    func GotoCamera(){
        self.performSegueWithIdentifier("Camerasegue",sender: nil)
    }
}

我用扩展解决了这个问题：

override func viewDidLoad() {
    super.viewDidLoad()

    let tapGR = UITapGestureRecognizer(target: self,action: #selector(PostlistViewController.handleTap(_:)))
    tapGR.delegate = self
    tapGR.numberOfTapsrequired = 2
    view.addGestureRecognizer(tapGR)
}

extension MainBoardController: UIGestureRecognizerDelegate {
    func handleTap(_ gesture: UITapGestureRecognizer){
        print("doubletapped")
    }
}