ios - 点击时 UIBarButtonItem 不调用另一个类中的函数

Question

我正在尝试将大部分代码移动到另一个文件；我相信我已经这样做了，但是，我在调用函数时遇到了问题。

我有两个文件:

scannerBrain.swift

var parentView = UIViewController()

func startScan(){
//The code I want to execute is here
}

scannerViewController.swift

let scanner = scannerBrain()
scanner.parentView = self
let rightButton = UIBarButtonItem(barButtonSystemItem: .add, target: scanner, action: #selector(scanner.startScan))
navigationItem.rightBarButtonItem = rightButton

这个编译很好，除了 startScan 从未被调用。我尝试将 rightButton 的目标更改为 self，但这导致了 unrecognised selector sent to instance

崩溃

感谢任何帮助

Answer 1

scanner 应该是类级别的属性，否则会被释放。像这样。

class TestViewController: UIViewController {

    let scanner = scannerBrain()

    override func viewDidLoad() {
        super.viewDidLoad()

        scanner.parentView = self
        let rightButton = UIBarButtonItem(barButtonSystemItem: .add, target: scanner, action: #selector(scanner.startScan))
        navigationItem.rightBarButtonItem = rightButton
    }
}