Question

基本上，我试图将16个不同的变量从一个视图控制器传递到另一个视图控制器，但只传递了底部的8个对手变量。我不确定我做错了什么，或者为什么只有那些8（特别是＃34;对手＆＃34;共同的）被传递。我是XCode的新手，所以任何可以帮助我的东西都会很棒。打印线正在测试是否发送变量，第一个不起作用，第二个起作用。

    //
//  ThirdViewController.swift
//  rally
//
//  Created by GBernero on 12/6/16.
//  Copyright © 2016 GBernero. All rights reserved.
//

import UIKit

class ThirdViewController: UIViewController {

    @IBOutlet weak var emptyTennisCourt: UIImageView!
    @IBOutlet weak var labelOpponent: UILabel!
    @IBOutlet weak var labelPlayer: UILabel!

    var playerWinners = 0 //holds total amount of winners player has hit
    var playerShortWinners = 0 //holds amount of winners play has hit short
    var playerDeepWinners = 0 //holds amount of winners play has hit deep
    var playerErrors = 0 //holds total amount of errors play has hit
    var playerErrorsLeft = 0 //holds amount of errors play has hit left
    var playerErrorsRight = 0 //holds amount of errors play has hit right
    var playerErrorsDeep = 0 //holds amount of errors play has hit deep
    var playerErrorsNet = 0 //holds amount of errors play has hit in the net
    var opponentWinners = 0 //holds total amount of winners opponent has hit
    var opponentShortWinners = 0 //holds amount of winners opponent has hit short
    var opponentDeepWinners = 0 //holds amount of winners opponent has hit deep
    var opponentErrors = 0 //holds total amount of errors opponent has hit
    var opponentErrorsLeft = 0 //holds amount of errors opponent has hit left
    var opponentErrorsRight = 0 //holds amount of errors opponent has hit right
    var opponentErrorsDeep = 0 //holds amount of errors opponent has hit deep
    var opponentErrorsNet = 0 //holds amount of errors opponent has hit in the net

    override func prepare(for segue: UIStoryboardSegue, sender: Any?)
    {
        let dvc = segue.destination as! SixthViewController
        dvc.playerErrorsDeep = self.playerErrorsDeep
        print("segueing from self \(self.playerErrorsDeep) to dvc: \(dvc.playerErrorsDeep)")
        dvc.playerErrorsNet = self.playerErrorsNet
        dvc.playerErrorsLeft = self.playerErrorsLeft
        dvc.playerErrorsRight = self.playerErrorsRight
        dvc.playerErrors = self.playerErrors
        dvc.playerShortWinners = self.playerShortWinners
        dvc.playerDeepWinners = self.playerDeepWinners
        dvc.playerWinners = self.playerWinners
        dvc.opponentErrorsDeep = self.opponentErrorsDeep
        print("segueing to dvc2: \(dvc.opponentErrorsDeep)")
        dvc.opponentErrorsNet = self.opponentErrorsNet
        dvc.opponentErrorsLeft = self.opponentErrorsLeft
        dvc.opponentErrorsRight = self.opponentErrorsRight
        dvc.opponentErrors = self.opponentErrors
        dvc.opponentShortWinners = self.opponentShortWinners
        dvc.opponentDeepWinners = self.opponentDeepWinners
        dvc.opponentWinners = self.opponentWinners

    }

    override func viewDidLoad()
    {
        self.navigationItem.setHidesBackButton(true, animated: false) //removes back button from access by user

        self.view.backgroundColor = UIColor(patternImage: UIImage(named: "tennis_background.jpg")!) //sets background of view controller to the background image


        super.viewDidLoad()
    }

    @IBAction func youErrorDeep(_ sender: Any)
    {
        playerErrors += 1
        playerErrorsDeep += 1
        print("deep \(playerErrors), \(playerErrorsDeep)")
    }
    @IBAction func youErrorLeft(_ sender: Any)
    {
        playerErrors += 1
        playerErrorsLeft += 1
    }

    @IBAction func youErrorRight(_ sender: Any)
    {
        playerErrors += 1
        playerErrorsRight += 1
    }

    @IBAction func youWinnerDeep(_ sender: Any)
    {
        playerWinners += 1
        playerDeepWinners += 1
    }

    @IBAction func youWinnerShort(_ sender: Any)
    {
        playerWinners += 1
        playerShortWinners += 1
    }

    @IBAction func youErrorNet(_ sender: Any)
    {
        playerErrors += 1
        playerErrorsNet += 1
    }

    @IBAction func opponentErrorDeep(_ sender: Any)
    {
        opponentErrors += 1
        opponentErrorsDeep += 1
        print( "it happens")
    }

    @IBAction func opponentErrorLeft(_ sender: Any)
    {
        opponentErrors += 1
        opponentErrorsLeft += 1
    }

    @IBAction func opponentErrorRight(_ sender: Any)
    {
        opponentErrors += 1
        opponentErrorsRight += 1
    }

    @IBAction func opponentWinnerDeep(_ sender: Any)
    {
        opponentWinners += 1
        opponentDeepWinners += 1
    }

    @IBAction func opponentWinnerShort(_ sender: Any)
    {
        opponentWinners += 1
        opponentShortWinners += 1
    }

    @IBAction func opponentErrorNet(_ sender: Any)
    {
        opponentErrors += 1
        opponentErrorsNet += 1
    }




    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */


}

Answer 1

您发布了大量代码，并告诉我们您用print语句替换为print("segueing from self \(self.playerErrorsDeep) to dvc: \(dvc.playerErrorsDeep)")语句时

playerErrorsDeep

...然后显示：

从self 0到dvc：0

因此，问题恰好在0调用prepareForSegue时出现dvc。所以问题不在于，为什么playerErrorsDeep的价值不会被设定？＆＃34;而是＆＃34;为什么0 yourErrorDeep？＆＃34;

让我问一下这个问题：调用@IBAction的控件是否还附加了一个segue？如果您同时拥有segue和@IBAction（或多个@IBAction），则无法保证他们被调用的顺序。

您应该从按钮中删除segue，并让@IBAction在完成更新值时以编程方式调用segue，而不是拥有@IBAction和segue的控件。所以，你应该：

删除按钮和下一个场景之间的segue;
相反，通过 control -dragging从＆＃34;第三个＆＃34;上面的视图控制器图标添加视图控制器之间的segue。场景到＆＃34;第六＆＃34;场景：
选择该segue并为其指定标识符：
让你的@IBAction func youErrorDeep(_ sender: Any) { playerErrors += 1 playerErrorsDeep += 1 print("deep \(playerErrors), \(playerErrorsDeep)") performSegue(withIdentifier: "GoToSixth", sender: self) }做你想做的任何更新，然后以编程方式执行segue：
```
@IBAction
```

这将确保首先执行playerErrorsDeep，然后它将以编程方式将segue调用到下一个场景。到那时，sbt package将具有您期望的值。

我试图在视图控制器之间传递数据，但我的16个变量中只有一半传递了？

1 个答案: