如何拦截swift iOS应用程序的关键事件？

Question

我删除了AppDelegate.swift中的@UIApplicationMain并写了main.swift如下，但程序仍然无法触发keyPressed函数。但是每次按键都会执行print("send event2")。

如何触发keyPressed函数？这个程序有问题吗？

import UIKit
import Foundation

class TApplication: UIApplication {
    override func sendEvent(_ event: UIEvent!) {
       super.sendEvent(event)
    }

    override var keyCommands: [UIKeyCommand]? {
      print("send event2") // this is an example
        return [
            UIKeyCommand(input: "1", modifierFlags: [], action: Selector(("keyPressed:")), discoverabilityTitle: “1”),
            UIKeyCommand(input: "2", modifierFlags: .shift, action: Selector("keyPressed:"), discoverabilityTitle: “2”)]
        ]
    }

    func keyPressed(sender: UIKeyCommand) {
        print("keypressed event !!!!!!!!") // this is an example
    }
}

Answer 1

我将'selector'修改为#selector（swift 3），终于解决了问题，可能有bug