UIGestureRecognizer 导致未捕获的异常错误。它说无法识别的选择器发送到实例。我正在使用 Swift 3 和 Xcode 8。
这是代码。
import UIKit
import UIKit.UIGestureRecognizer
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
print("starting")
var swipeDown = UISwipeGestureRecognizer(target: self, action:
"respondToSwipeGesture:")
swipeDown.direction = UISwipeGestureRecognizerDirection.down
self.view.addGestureRecognizer(swipeDown)
}
func respondToSwipeGesture(gesture: UIGestureRecognizer) {
if let swipeGesture = gesture as? UISwipeGestureRecognizer {
switch swipeGesture.direction {
case UISwipeGestureRecognizerDirection.down:
// go to View Controller 2
gopage2()
default:
print("does it work? ")
break
}
}
}
func gopage2() {
let storyboard=UIStoryboard(name: "Main", bundle: nil)
let viewController =
storyboard.instantiateViewController(withIdentifier: "ViewController2")
as! UIViewController
self.present(viewController, animated: true) }
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
respondToSwipeGesture 是否需要成为公共(public)类？
最佳答案
只需在参数中添加“忽略此”下划线即可。
func respondToSwipeGesture(_ gesture: UIGestureRecognizer) {
关于swift - UIGestureRecognizer 导致未捕获的异常错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40428968/