ios - 是否可以在ViewController文件之外设置约束和对象？

我对不使用故事板的编程很陌生。我要做的是移动负责初始化UIView和约束的代码，从那里我也希望把它们放到另一个文件中。
理想情况下，我想打一个电话
view.addSubview（loginControllerObjects（frame:view.frame））视图
从我的viewDidLoad（）调用那个单独的文件并在适当的位置设置对象，以保持ViewController的整洁。
我已经解决了大部分问题，但似乎我的函数setUpInputContainer（）给了我一个“以NSException类型的意外异常终止”错误。建议在不同的视图层次结构中，由于其锚定了引用项。有人知道如何解决这个问题吗？
程序委托

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    window = UIWindow(frame: UIScreen.main.bounds)

    let homeViewController = ViewController()
    window?.rootViewController = UINavigationController(rootViewController: homeViewController)
    window!.makeKeyAndVisible()

    return true

}

视图控制器

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.isNavigationBarHidden = true
    view.addSubview(loginControllerContraints(frame: view.frame))
}

}

extension UIColor {
    convenience init(r: CGFloat, g: CGFloat, b: CGFloat) {
        self.init(red: r/255, green: g/255, blue: b/255, alpha: 1)
    }
}

物流控制合同

class loginControllerContraints: UIView {

override init(frame: CGRect) {
    super.init(frame: frame)

    backgroundColor = UIColor(r: 61, g: 91, b: 151)
    setUpInputContainer()
    addSubview(inputsContainerView)

}

let inputsContainerView: UIView = {
    let view = UIView()
    let red = UIColor.red
    view.backgroundColor = UIColor.white
    view.translatesAutoresizingMaskIntoConstraints = false
    view.layer.cornerRadius = 5
    view.layer.backgroundColor = red.cgColor
    view.layer.masksToBounds = true
    return view
}()

var inputsContainerViewHeightAnchor: NSLayoutConstraint?

func setUpInputContainer() {
    //Needs x, y, height, and width constraints for INPUTCONTAINER
    inputsContainerView.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
    inputsContainerView.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
    inputsContainerView.widthAnchor.constraint(equalTo: widthAnchor, constant: -24).isActive = true
    inputsContainerViewHeightAnchor = inputsContainerView.heightAnchor.constraint(equalToConstant: 150)
    inputsContainerViewHeightAnchor?.isActive = true


}

//Required do not touch
required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}


}

最佳答案

问题是，在将setUpInputContainer添加到inputsContainerView之前，先调用loginControllerContraints。
若要修复此问题，请在添加任何inputsContainerView约束之前将loginControllerContraints添加到inputsContainerView。用下面的代码替换init方法。

override init(frame: CGRect) {
    super.init(frame: frame)

    backgroundColor = UIColor(r: 61, g: 91, b: 151)
    addSubview(inputsContainerView)
    setUpInputContainer()
}