Swift 3如何在func中解析EXC_BAD_ACCESS

Question

I have the following class:

import UIKit

class ErrorMessageLabel: UILabel {
    open func setErrorText(button:UIButton?, message:String) {
        self.text = message
        self.isHidden = (message == "")
        if (button != nil) {button?.isEnabled = (message == "")}
    }
}

which I use in a View Controller:

class RegistrationViewController: SuperViewController {
    @IBOutlet weak var errorMessageLabel: ErrorMessageLabel!

    @IBOutlet weak var registerButton: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()

        checkValidData()
    }

    private func checkValidData()
    {
        errorMessageLabel.setErrorText(registerButton, message: "")
        ...
    }

I get Thread 1: EXC_BAD_ACCESS (code=2, address=...) on the setErrorText call

If i change the ErrorMessageLabel.swift to the following

import UIKit

extension UILabel {
    open func setErrorText(button:UIButton?, message:String) {
        self.text = message
        self.isHidden = (message == "")
        if (button != nil) {button?.isEnabled = (message == "")}
    }
}

class ErrorMessageLabel: UILabel {
}

the code works. Obviously, this is the wrong place to put the setErrorText as the code does not apply to all UILabels. What is the proper fix?

I'm a relative newbie to IOS development.

Answer 1

您需要将视图中的标签类（故事板或笔尖）更改为ErrorMessageLabel，可在此处找到： http : //prntscr.com/flkor0