Detect direction swiped UISwipeGestureRecognizer

Question

For my own convenience, I have created a single UISwipeGestureRecognizer allowing the user to swipe left and right invoking the same action in code.
I was wondering whether it is possible to detect the actual direction the user swiped inside its action. I found this post点击次数，但可能会使用Swift进行更改。

Answer 1

重申@LinusGeffarth这是我能提出的最佳解决方案

import UIKit

class SwipeUTIL {
    static func addSwipe(selfVC: UIViewController) {
        let swipeLeft = UISwipeGestureRecognizer(target: selfVC, action: #selector(selfVC.didSwipe))
        let swipeRight =  UISwipeGestureRecognizer(target: selfVC, action: #selector(selfVC.didSwipe))

        swipeLeft.direction = .left
        swipeRight.direction = .right

        selfVC.view!.addGestureRecognizer(swipeRight)
        selfVC.view!.addGestureRecognizer(swipeLeft)
    }

}

extension UIViewController {
    internal func didSwipe(swipe: UISwipeGestureRecognizer, completion: (@escaping(UISwipeGestureRecognizerDirection) -> Void)) {
        completion(swipe.direction)
    }
}

在视图控制器中

 override func viewDidLoad() {
        super.viewDidLoad()
        SwipeUTIL.addSwipe(selfVC: self)
    }

    override func didSwipe(swipe: UISwipeGestureRecognizer, completion: @escaping ((_ swipedir: UISwipeGestureRecognizerDirection) -> Void)) {
        print(swipe.direction)
    }