从另一个文件访问Swift变量

Question

我是一名新手Swift程序员，我被要求编写一个应用程序，允许你输入一个单词，然后生成一个随机的俳句（poem） 。这是一个带有两个ViewControllers的选项卡应用程序。 在第一个ViewController中，我有数据，并且我想以良好的方式显示该数据在第二个ViewController中。我已经将所有的诗行和数据都放在了第一个ViewController中，但我想在第二个ViewController中访问这些变量。我尝试创建了一个函数，仅返回它们，在第二个ViewController中调用该函数，但没有任何结果，因为该函数只返回了nil。如果你们中的任何一个人能够帮助，我会很高兴。 谢谢！

以下是第一个ViewController:

import UIKit
import Foundation


class FirstViewController: UIViewController, UITextFieldDelegate {

@IBOutlet weak var keyWordTextField: UITextField!

@IBOutlet weak var syllableSlider: UISlider!   
@IBOutlet weak var syllableSliderLabel: UILabel!
var syllableSliderValue = 1


@IBOutlet weak var lineOneTextField: UITextField!

@IBOutlet weak var lineTwoTextField: UITextField!
@IBOutlet weak var lineThreeTextField: UITextField!


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    lineOneTextField.text = "Rad 1"
    lineTwoTextField.text = "Rad 2"
    lineThreeTextField.text = "Rad 3"


}

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

@IBAction func syllableValueChanged(sender: UISlider) {
    syllableSliderValue = Int((sender.value))
    syllableSliderLabel.text = "Ordet har: \(syllableSliderValue) stavelser"
}


@IBAction func getNewHaiku() {
    if keyWordTextField.text != "" {
        let keyWord = keyWordTextField.text
        let lineOne = generateLine(keyWord: keyWord, syllables: syllableSliderValue,        lineSyllableLenght: 5)
        let lineTwo = generateLine(keyWord: keyWord, syllables: syllableSliderValue, lineSyllableLenght: 7)
        let lineThree = generateLine(keyWord: keyWord, syllables: syllableSliderValue,  lineSyllableLenght: 5)
        lineOneTextField.text! = lineOne
        lineTwoTextField.text! = lineTwo
        lineThreeTextField.text! = lineThree
    }

}
func generateLine(#keyWord: String, syllables : Int, lineSyllableLenght : Int) -> String {
    let oneSyllables = Dict().oneSyllables
    let twoSyllables = Dict().twoSyllables
    let threeSyllables = Dict().threeSyllables
    let fourSyllables = Dict().fourSyllables

    let randomOneSyllableWordNumber = Int(arc4random_uniform(UInt32(oneSyllables.count)))
    let randomTwoSyllableWordNumber = Int(arc4random_uniform(UInt32(twoSyllables.count)))
    let randomThreeSyllableWordNumber = Int(arc4random_uniform(UInt32(threeSyllables.count)))
    let randomFourSyllableWordNumber = Int(arc4random_uniform(UInt32(fourSyllables.count)))

    var lineArray : [String] = []
    var line = ""
    lineArray.append(keyWord)

    if syllables == 1 {
        let randomWordMethod = Int(arc4random_uniform(2))

        if randomWordMethod == 0 {

            lineArray.append(fourSyllables[randomFourSyllableWordNumber])

        } else if randomWordMethod == 1 {

            lineArray.append(threeSyllables[randomThreeSyllableWordNumber])
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
        } else if randomWordMethod == 2 {

            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
            lineArray.append(twoSyllables[randomOneSyllableWordNumber])
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
        }

    } else if syllables == 2 {
        let randomWordMethod = Int(arc4random_uniform(2))

        if randomWordMethod == 0 {

            lineArray.append(twoSyllables[randomOneSyllableWordNumber])
            lineArray.append(oneSyllables[randomTwoSyllableWordNumber])
        } else if randomWordMethod == 1 {

            lineArray.append(threeSyllables[randomThreeSyllableWordNumber])
        } else if randomWordMethod == 2 {
            lineArray.append(twoSyllables[randomTwoSyllableWordNumber])
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
        }
    } else if syllables == 3 {
        let randomWordMethod = Int(arc4random_uniform(1))

        if randomWordMethod == 0 {
            lineArray.append(twoSyllables[randomTwoSyllableWordNumber])
        } else if randomWordMethod == 1 {
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
        }

    } else if syllables == 4 {
        lineArray.append(oneSyllables[randomOneSyllableWordNumber])
    }

    if lineSyllableLenght == 7 {
        let randomWordMethod = Int(arc4random_uniform(1))

        if randomWordMethod == 0 {
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
            lineArray.append(oneSyllables[randomOneSyllableWordNumber])
        } else if randomWordMethod == 1 {
            lineArray.append(twoSyllables[randomTwoSyllableWordNumber])
        }
    }
    for word in lineArray {
        line += " \(word)"
    }
    line += ","

    return line
}

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    self.view.endEditing(true)
}
func getData() -> (line2: String, line3: String) {

    return (lineTwoTextField.text, lineThreeTextField.text)

}


}

Ps，“Dict”是另一个文件，但只包含单词。

第二个视图控制器为空白的。

- David Wolters

---

我尝试创建一个函数，什么也不做，只是返回它们，然后在SecondViewController中调用该函数。我们需要看到您尝试的这个函数以及您如何尝试从第二个视图控制器调用它。您发布的代码对于解决问题没有用处。 - rdelmar

func getData() -> (String, String, String) { return (lineOneTextField.text, lineTwoTextField.text, lineThreeTextField.text) } 获取数据函数() -> (字符串，字符串，字符串) { 返回(lineOneTextField.text, lineTwoTextField.text, lineThreeTextField.text) } - David Wolters

是的，你是如何尝试从你的第二个控制器调用它的？ - rdelmar

我在名为“override func viewDidAppear(animated: Bool)”的函数中创建了第一个视图控制器的实例： let firstViewController = FirstViewController() let data = firstViewController.getData() lineOneLabel.text = data.line1 lineTwoLabel.text = data.line2 lineThreeLabel.text = data.line3 - David Wolters

let firstViewController = FirstViewController() 创建了一个新的 FirstViewController 实例，它并没有获取到你已经拥有的那个实例的引用。 - rdelmar

Answer 1

或者你可以将它设为全局变量，以便任何文件都可以访问它。

struct structname {
    static var yourvariable = value
}

调用时，您需要输入

filename.structname.yourvariable

- White Phantom

Answer 2

在第二个视图控制器中，您需要像这样传递实例：

var firstViewController: FirstViewController?

然后在了解两者之间的主实例中:

secondViewController.firstViewController = firstViewController

（例如在awakeFromNib中）假定它们在主实例中已知，类似于…

let firstViewController = FirstViewController()
let secondViewController = SecondViewController()

最后，在SecondViewController中，您可以访问第一个视图控制器：

firstViewController?.generateLine....

- qwerty_so