无法识别的选择器发送到类 [英] Unrecognized selector sent to class

问题描述

我已经看到，这是一个常见问题，但我找不到任何适合自己的解决方案.

I've seen that, this is a common issue but i couldn't find any solution for myself.

代码如下:

class ButtonViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(button)
    }

    func exmp(sender: UIButton) {
        print("hello world")
    }

    let button: UIButton = {
        let but = UIButton(frame: CGRect(x: 33, y: 33, width: 33, height: 33))
        but.setTitle("-", for: .normal)
        but.titleLabel?.textColor = UIColor.white
        but.layer.cornerRadius = 10
        but.backgroundColor = UIColor.red
        but.addTarget(ButtonViewController.self, action: #selector(ButtonViewController.exmp(sender:)), for: .touchDown)
        return but
    }
}

问题:出现红色按钮，但当我点击它时，我收到无法识别的选择器发送到类"错误.

Issue: The red button appears but when i click it i get the "Unrecognized selector sent to class" error.

感谢任何帮助！谢谢.

推荐答案

您收到无法识别的选择器发送到类，因为您设置了错误的目标.目标应该是 self 而不是 ButtonViewController.self:

You are getting Unrecognized selector sent to class because you have set the wrong target. The target should be self and not ButtonViewController.self:

but.addTarget(self, action: #selector(ButtonViewController.exmp(sender:)), for: .touchDown)

您的 #selector 有效，但对于 Swift 3，您应该将操作编写为 func exmp(_ sender: UIButton) { 制作选择器 #selector(exmp(_:)).注意:无论是否重写exmp，都可以将选择器简化为#selector(exmp).

Your #selector works, but for Swift 3 you should write the action as func exmp(_ sender: UIButton) { making the selector #selector(exmp(_:)). Note: whether or not you rewrite exmp, you can simplify the selector to just #selector(exmp).

这篇关于无法识别的选择器发送到类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！