Ios 当包含以编程方式显示的视图控制器时，发现IBOutlet引用为零

我正在构建一个正在运行的应用程序，并试图在点击开始运行按钮时以编程方式呈现一个视图控制器。但是，当我在设置presenting view控制器后点击该按钮时，在按调用顺序展开IBOutlet时，会发现对IBOutlet的任何引用均为零

值得注意的是，当我通过故事板将两个视图控制器连接为“show”时，一切正常，但我希望以编程方式全屏显示视图控制器，而不是默认的卡片式显示

从显示视图控制器：

@IBAction func startRunTapped(_ sender: Any) {
    let inRunVC = CurrentRunVC()
    inRunVC.modalPresentationStyle = .fullScreen
    self.present(inRunVC, animated: true, completion: nil)
}

import UIKit
import MapKit

class CurrentRunVC: LocationVC {


@IBOutlet weak var sliderImageView: UIImageView!
@IBOutlet weak var swipeBGImageView: UIImageView!
@IBOutlet weak var durationLabel: UILabel!
@IBOutlet weak var paceLabel: UILabel!
@IBOutlet weak var distanceLabel: UILabel!
@IBOutlet weak var pauseButton: UIButton!

var startLocation: CLLocation!
var lastLocation: CLLocation!
var timer = Timer()

var runDistance = 0.0
var pace = 0
var counter = 0

override func viewDidLoad() {
    super.viewDidLoad()
    let swipeGesture = UIPanGestureRecognizer(target: self, action: #selector(endRunSwiped(sender:)))
    sliderImageView.addGestureRecognizer(swipeGesture) //error unwrapping here
    sliderImageView.isUserInteractionEnabled = true    // and here
    swipeGesture.delegate = self as? UIGestureRecognizerDelegate
} 

//errors also on any other reference to an IBOutlet

从显示的视图控制器：

@IBAction func startRunTapped(_ sender: Any) {
    let inRunVC = CurrentRunVC()
    inRunVC.modalPresentationStyle = .fullScreen
    self.present(inRunVC, animated: true, completion: nil)
}

import UIKit
import MapKit

class CurrentRunVC: LocationVC {


@IBOutlet weak var sliderImageView: UIImageView!
@IBOutlet weak var swipeBGImageView: UIImageView!
@IBOutlet weak var durationLabel: UILabel!
@IBOutlet weak var paceLabel: UILabel!
@IBOutlet weak var distanceLabel: UILabel!
@IBOutlet weak var pauseButton: UIButton!

var startLocation: CLLocation!
var lastLocation: CLLocation!
var timer = Timer()

var runDistance = 0.0
var pace = 0
var counter = 0

override func viewDidLoad() {
    super.viewDidLoad()
    let swipeGesture = UIPanGestureRecognizer(target: self, action: #selector(endRunSwiped(sender:)))
    sliderImageView.addGestureRecognizer(swipeGesture) //error unwrapping here
    sliderImageView.isUserInteractionEnabled = true    // and here
    swipeGesture.delegate = self as? UIGestureRecognizerDelegate
} 

//errors also on any other reference to an IBOutlet

我已经确认所有IBO插座都连接正确

故事板：

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提前感谢

您的视图控制器的输出在情节提要中定义，并在从情节提要加载视图控制器时创建。在此行中初始化新的视图控制器时：

let inRunVC = CurrentRunVC()

然后，系统将查找与视图控制器同名的xib文件，该文件不存在，这意味着它只加载一个没有连接插座的空白视图。所有这些隐式展开的选项现在都为零

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或者从按钮到同一视图控制器创建一个新的序列，但创建一个模态表示，或者在序列图像板中添加对显示视图控制器的引用，然后使用当前序列图像板的Instatitate with identifier方法加载它。

您不是在获取当前VC的正确序列图像板实例，而是在创建一个新的序列图像板实例。使用

let runVC = self.storyboard?.instantiateViewController(withIdentifier: "CurrentRunVC") as! CurrentRunVC //set the identifier in the storyboard identity inspector

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您没有初始化ViewController并将其与其情节提要版本连接。您需要使用

UIStoryboard（名称：“storyboardName”，bundle:nil）！CurrentRunVC`但对于故事板，您可以选择“以模式呈现”而不是“显示”，然后选择“演示”：“全屏”