Swift Xcode跳过if-else语句

我的if-else语句检查某些文本字段是否为空，如果为空，则弹出警报。然而，xcode即使完成了所有工作，也会转到其他函数

有一个if语句，它检查分段控件的值，并相应地检查一些文本字段

@IBAction func calc(_ sender: Any) {
    
    // Check if dilution text field is empty
    let dilutiontext = self.dilution.text
    if (dilutiontext?.isEmpty ?? true) {
        Alert.showAlert(on: self, with: "Empty Fields", message: "Dilution field is empty")
    }
    if choose.selectedSegmentIndex == 0 {
        
        if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true {
            Alert.showAlert(on: self, with: "Empty Fields", message: "Number 1-4 fields should not be empty")
        } else {
            performSegue(withIdentifier: "turner", sender: self)
        }
    } else {
        if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true || self.number5.text?.isEmpty ?? true || self.number6.text?.isEmpty ?? true || self.number7.text?.isEmpty ?? true || self.number8.text?.isEmpty ?? true {
            Alert.showAlert(on: self, with: "Empty Fields", message: "Number 1-8 fields should not be empty")
        } else {
            performSegue(withIdentifier: "turner", sender: self)
        }
    }
    
}

我有另一个控制警报的文件alert.swift：

import Foundation
import UIKit

struct Alert {
    public static func showAlert(on vc: UIViewController, with title: String, message: String) {
        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
        vc.present(alert, animated: true)
    }
}

编辑：

以前是self.dilution.text？.isEmpty，现在让dilutiontext=self.dilution.text和dilutiontext？isEmpty

我注释掉了prepare for segue功能，令人惊讶的是警报开始工作。我仍然需要该功能和警报工作虽然。以下是函数：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    
    var vc = segue.destination as! SecondViewController
    
    if choose.selectedSegmentIndex == 0 {
        vc.n1 = Int(number1.text!)!
        vc.n2 = Int(number2.text!)!
        vc.n3 = Int(number3.text!)!
        vc.n4 = Int(number4.text!)!
        vc.dil = Int(dilution.text!)!
        vc.cn = Int(choose.selectedSegmentIndex)

    } else {
        vc.n1 = Int(number1.text!)!
        vc.n2 = Int(number2.text!)!
        vc.n3 = Int(number3.text!)!
        vc.n4 = Int(number4.text!)!
        vc.n5 = Int(number5.text!)!
        vc.n6 = Int(number6.text!)!
        vc.n7 = Int(number7.text!)!
        vc.n8 = Int(number8.text!)!
        vc.cn = Int(choose.selectedSegmentIndex)
        vc.dil = Int(dilution.text!)!
    }

}

当我运行它时，它不会显示警报（检查文本字段是否为空），而是继续执行segue函数，并在展开可选值时显示意外的find nil，这是预期值，显然“if”和“else if”条件都不是真的。加

let dilutiontext = self.dilution.text
let celltext = self.cell.text

---

然后设置断点并检查值。

显然，如果segue函数中的一个if条件为true，则跳过警报。因此，如果一开始有什么东西会使这些声明成为虚假的，那么在经过警报之后，它会使它们成为真实的，那么问题就解决了

因此，我在segue func中为if和if else语句分别创建了两个函数

func option1() -> Bool {
    if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true || self.dilution.text?.isEmpty ?? true || !(self.number5.text?.isEmpty ?? true) || !(self.number6.text?.isEmpty ?? true) || !(self.number7.text?.isEmpty ?? true) || !(self.number8.text?.isEmpty ?? true) {
        return false
    } else {
        return true
    }
}

func option2() -> Bool {
    if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true || self.number5.text?.isEmpty ?? true || self.number6.text?.isEmpty ?? true || self.number7.text?.isEmpty ?? true || self.number8.text?.isEmpty ?? true || self.dilution.text?.isEmpty ?? true {
        return false
    } else {
        return true
    }
}

检查所有条件是否为真，如果为真，则返回真，以便程序可以继续执行segue func

func option1() -> Bool {
    if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true || self.dilution.text?.isEmpty ?? true || !(self.number5.text?.isEmpty ?? true) || !(self.number6.text?.isEmpty ?? true) || !(self.number7.text?.isEmpty ?? true) || !(self.number8.text?.isEmpty ?? true) {
        return false
    } else {
        return true
    }
}

func option2() -> Bool {
    if (self.number1.text?.isEmpty) ?? true || self.number2.text?.isEmpty ?? true || self.number3.text?.isEmpty ?? true || self.number4.text?.isEmpty ?? true || self.number5.text?.isEmpty ?? true || self.number6.text?.isEmpty ?? true || self.number7.text?.isEmpty ?? true || self.number8.text?.isEmpty ?? true || self.dilution.text?.isEmpty ?? true {
        return false
    } else {
        return true
    }
}

segue将检查条件是否为真，如果不是，它将通过警报，从而使option1（）或option2（）返回真-因此segue func中的if条件将为真，以便程序继续

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    
    var vc = segue.destination as! SecondViewController

    if option1() == true {
        vc.n1 = Int(number1.text!)!
        vc.n2 = Int(number2.text!)!
        vc.n3 = Int(number3.text!)!
        vc.n4 = Int(number4.text!)!
        vc.dil = Int(dilution.text!)!
        vc.cn = Int(choose.selectedSegmentIndex)

    } else if option2() == true {
        vc.n1 = Int(number1.text!)!
        vc.n2 = Int(number2.text!)!
        vc.n3 = Int(number3.text!)!
        vc.n4 = Int(number4.text!)!
        vc.n5 = Int(number5.text!)!
        vc.n6 = Int(number6.text!)!
        vc.n7 = Int(number7.text!)!
        vc.n8 = Int(number8.text!)!
        vc.cn = Int(choose.selectedSegmentIndex)
        vc.dil = Int(dilution.text!)!
    }

}

---

谢谢你的帮助。我确实检查了if语句是否正确，我还对所有if、else if和else使用了警报，但仍然没有出现任何警报。还在想办法吗