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ios - 塞格街的噩梦

问题描述

应用程序应该做什么：

1) 用户在 textField 中输入一个单词并点击相应的按钮

2) 应用程序应该转到另一个包含两个标签的场景。一个应该显示用户输入的单词，另一个标识被点击的按钮。这些数据应该通过接收 ViewController 上的属性传递。

它实际上做了什么：

1) segue 立即被调用，显然绕过prepare(segue: sender:)

2) 两个标签都是空白的

3) 断点并print()指示prepare(segue: sender:)从不调用

我检查过/尝试过的内容：

1）根据我的print()陈述，按钮在情节提要中具有正确的标签

2）我已经替换if else了switch

3）我很确定我已经阅读了关于 SO 的所有相关问题和答案

4 sender)prepare(segue: sender:)再次来回Any?切换UIButton

编码

import UIKit





class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }




    @IBOutlet weak var textField: UITextField!

    @IBOutlet weak var tf2: UITextField!

    @IBOutlet weak var tf3: UITextField!

    @IBOutlet weak var tf4: UITextField!




    @IBAction func sendButton(_ sender: UIButton) {
        print("sender.tag is \(sender.tag)")

        self.performSegue(withIdentifier: "mySegue", sender: sender)

        print("sender.tag is \(sender.tag)")
    }
    @IBAction func button2(_ sender: UIButton) {
        print("sender.tag is \(sender.tag)")

        self.performSegue(withIdentifier: "mySegue", sender: sender)

        print("sender.tag is \(sender.tag)")
    }
    @IBAction func button3(_ sender: UIButton) {
        print("sender.tag is \(sender.tag)")

        self.performSegue(withIdentifier: "mySegue", sender: sender)

        print("sender.tag is \(sender.tag)")
    }
    @IBAction func button4(_ sender: UIButton) {
        print("sender.tag is \(sender.tag)")

        self.performSegue(withIdentifier: "mySegue", sender: sender)

        print("sender.tag is \(sender.tag)")
    }

    func prepare(for segue: UIStoryboardSegue, sender: UIButton) {

        print("Inside prepare for segue")
        print("sender.tag is \(sender.tag)")

        if segue.identifier == "mySegue" {

            let vc = segue.destination as! SecondViewController
            print("sender.tag is \(sender.tag)")

            switch sender.tag {

            case 101:
                if (textField.text?.count)! >= 1 {
                    vc.staticText = "Button 101"
                    vc.textProp = self.textField.text!
                    print("sender.tag is \(sender.tag)")
                }

            case 102:
                if (tf2.text?.count)! >= 1 {
                    vc.staticText = "Button 102"
                    vc.textProp = self.tf2.text!
                    print("sender.tag is \(sender.tag)")
                }

            case 103:
                if (tf3.text?.count)! >= 1 {
                    vc.staticText = "Button 103"
                    vc.textProp = self.tf3.text!
                    print("sender.tag is \(sender.tag)")
                }

            case 104:
                if (tf4.text?.count)! >= 1 {
                    vc.staticText = "Button 104"
                    vc.textProp = self.tf4.text!
                    print("sender.tag is \(sender.tag)")
                }
            default:
                print("Something went wrong")
            }



//                print("In FirstVC, vc.textProp = \(vc.textProp)")
            }else{
                print("No text in textField...")
            }
        }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

我承认我很擅长忽略显而易见的事情，但在打扰你们之前我确实花了很多时间。任何帮助或指导将不胜感激......

谢谢！

标签： iosswiftpropertiesswitch-statementuistoryboardsegue

解决方案

prepare(for segue没有被调用，因为签名是错误的。您不得更改sender参数的类型。

sender例如，在额外的行中转换为预期的类型

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "mySegue",
       let button = sender as? UIButton {
       ...

并将所有后续出现的 替换sender为button

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