问题
Hey my StackView is doing nothing, there are two problems: The first is that the elements on the VC are completely displaced when I turn around the simulator or change the device, so the StackView is not doing what it should do! The second thing is that the StackView is covering the navigation bar and I don't know how to make it visible. Can someone help me?
import UIKit
class RegisterViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
let stackView = UIStackView()
var profilePicture = UIButton()
var profileIcon = UIImage()
let usernameTextField = UITextField()
let emailTextField = UITextField()
let passswordTextField = UITextField()
let signInButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Create an Account"
view.backgroundColor = .white
// SetUp StackView:
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.alignment = .center
stackView.distribution = .fillEqually
stackView.spacing = 50
view.addSubview(stackView)
// SetUp Stack View Constraints:
stackView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
stackView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
//Add Elements
stackView.addArrangedSubview(profilePicture)
stackView.addArrangedSubview(usernameTextField)
stackView.addArrangedSubview(passswordTextField)
stackView.addArrangedSubview(signInButton)
// MARK: - Set-Up View-Elements
// SetUp ProfileIcon:
profileIcon = UIImage(named: "characteer")!
profilePicture.setImage(profileIcon, for: .normal)
profilePicture.imageView?.contentMode = .scaleAspectFill
let cornerRadius: CGFloat
cornerRadius = 75 // half of widht/height
profilePicture.layer.cornerRadius = cornerRadius
profilePicture.layer.masksToBounds = true
profilePicture.layer.borderWidth = 1
profilePicture.layer.borderColor = UIColor.white.cgColor
profilePicture.addTarget(self, action: #selector(handleSelectedPhoto), for: .touchUpInside)
view.addSubview(profilePicture)
profilePicture.translatesAutoresizingMaskIntoConstraints = false
profilePicture.heightAnchor.constraint(equalToConstant: 150).isActive = true
profilePicture.widthAnchor.constraint(equalToConstant: 150).isActive = true
profilePicture.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
profilePicture.topAnchor.constraint(equalTo: view.topAnchor, constant: 110).isActive = true
// SetUp UsernameTextfield:
usernameTextField.backgroundColor = .white
usernameTextField.attributedPlaceholder = NSAttributedString(string: "Username", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
usernameTextField.textAlignment = NSTextAlignment.center
usernameTextField.layer.cornerRadius = 8
usernameTextField.layer.borderWidth = 1
usernameTextField.layer.borderColor = UIColor.lightGray.cgColor
self.view.addSubview(usernameTextField)
let username = usernameTextField.text
usernameTextField.translatesAutoresizingMaskIntoConstraints = false
usernameTextField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
usernameTextField.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20).isActive = true
usernameTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
usernameTextField.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
// SetUpEmailTextfield:
emailTextField.backgroundColor = .white
emailTextField.attributedPlaceholder = NSAttributedString(string: "Email", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
emailTextField.textAlignment = NSTextAlignment.center
emailTextField.layer.cornerRadius = 8
emailTextField.layer.borderWidth = 1
emailTextField.layer.borderColor = UIColor.lightGray.cgColor
self.view.addSubview(emailTextField)
emailTextField.translatesAutoresizingMaskIntoConstraints = false
emailTextField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
emailTextField.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20).isActive = true
emailTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
emailTextField.topAnchor.constraint(equalTo: usernameTextField.bottomAnchor, constant: 20).isActive = true
```
回答1:
You're doing a number of things wrong... It would be well worth your while to go through a few tutorials on auto-layout and using UIStackView.
First, if you add a view (image view, text field, label, button, etc) to a stack view, do not also give those views position constraints. That's what the stack view is doing.
Second, once you've added a view:
stackView.addArrangedSubview(profilePicture)
do not then add it as a subview like this:
view.addSubview(profilePicture)
Doing that will remove profilePicture from the stack view.
Take a look through your code -- review the comments where I've made changes:
class RegisterViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
let stackView = UIStackView()
var profilePicture = UIButton()
var profileIcon = UIImage()
let usernameTextField = UITextField()
let emailTextField = UITextField()
let passswordTextField = UITextField()
let signInButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Create an Account"
view.backgroundColor = .white
// SetUp StackView:
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.alignment = .center
// distribution should be .fill NOT .fillEqually
stackView.distribution = .fill
stackView.spacing = 50
view.addSubview(stackView)
// SetUp Stack View Constraints:
stackView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
stackView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
//Add Elements
stackView.addArrangedSubview(profilePicture)
stackView.addArrangedSubview(usernameTextField)
stackView.addArrangedSubview(emailTextField)
stackView.addArrangedSubview(passswordTextField)
stackView.addArrangedSubview(signInButton)
// MARK: - Set-Up View-Elements
// SetUp ProfileIcon:
//profileIcon = UIImage(named: "characteer")!
profileIcon = UIImage(named: "pro1")!
profilePicture.setImage(profileIcon, for: .normal)
profilePicture.imageView?.contentMode = .scaleAspectFill
let cornerRadius: CGFloat
cornerRadius = 75 // half of widht/height
profilePicture.layer.cornerRadius = cornerRadius
profilePicture.layer.masksToBounds = true
profilePicture.layer.borderWidth = 1
profilePicture.layer.borderColor = UIColor.white.cgColor
//profilePicture.addTarget(self, action: #selector(handleSelectedPhoto), for: .touchUpInside)
// NO - it's already in the stack view
//view.addSubview(profilePicture)
// Set Only Width and Height - position is managed by the stack view
profilePicture.heightAnchor.constraint(equalToConstant: 150).isActive = true
profilePicture.widthAnchor.constraint(equalToConstant: 150).isActive = true
// SetUp UsernameTextfield:
usernameTextField.backgroundColor = .white
usernameTextField.attributedPlaceholder = NSAttributedString(string: "Username", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
usernameTextField.textAlignment = NSTextAlignment.center
usernameTextField.layer.cornerRadius = 8
usernameTextField.layer.borderWidth = 1
usernameTextField.layer.borderColor = UIColor.lightGray.cgColor
// NO - it's already in the stack view
// self.view.addSubview(usernameTextField)
let username = usernameTextField.text
// Set Only Width and Height - position is managed by the stack view
usernameTextField.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -40).isActive = true
usernameTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
// SetUpEmailTextfield:
emailTextField.backgroundColor = .white
emailTextField.attributedPlaceholder = NSAttributedString(string: "Email", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
emailTextField.textAlignment = NSTextAlignment.center
emailTextField.layer.cornerRadius = 8
emailTextField.layer.borderWidth = 1
emailTextField.layer.borderColor = UIColor.lightGray.cgColor
// NO - it's already in the stack view
// self.view.addSubview(emailTextField)
// Set Only Width and Height - position is managed by the stack view
emailTextField.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -40).isActive = true
emailTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
// SetUp PasswordTextfield:
passswordTextField.backgroundColor = .white
passswordTextField.attributedPlaceholder = NSAttributedString(string: "Password", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
passswordTextField.textAlignment = NSTextAlignment.center
passswordTextField.layer.cornerRadius = 8
passswordTextField.layer.borderWidth = 1
passswordTextField.layer.borderColor = UIColor.lightGray.cgColor
// NO - it's already in the stack view
// self.view.addSubview(emailTextField)
// Set Only Width and Height - position is managed by the stack view
passswordTextField.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -40).isActive = true
passswordTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
signInButton.setTitle("Sign In", for: [])
signInButton.backgroundColor = .blue
// Set Only Width and Height - position is managed by the stack view
signInButton.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -40).isActive = true
signInButton.heightAnchor.constraint(equalToConstant: 50).isActive = true
}
}
Of course, using that layout - where you specified vertical spacing between the elements of 50-pts, and you've set explicit heights for each element, you'll likely find that it doesn't "fit quite right" across different devices / screen sizes.
So, as pointed out to you in your previous question here: Why is my VC displaced after changing the Simulator? AutoLayout - you probably want to change the stack view's Distribution to Equal Spacing and add a bottom constraint:
stackView.distribution = .equalSpacing
stackView.spacing = 0
stackView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -20).isActive = true
That may or may not give you exactly what you want, but it's a starting point.
回答2:
Just I set for profilePicture and usernameTextField but for others are same it works. Wrong side of your code is about constraint and you add object two different views. There is a solution.
let stackView = UIStackView()
var profilePicture = UIButton()
var profileIcon = UIImage()
let usernameTextField = UITextField()
let emailTextField = UITextField()
let passswordTextField = UITextField()
let signInButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Create an Account"
view.backgroundColor = .white
// SetUp StackView:
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.alignment = .center
stackView.distribution = .fillEqually
stackView.spacing = 50
view.addSubview(stackView)
// SetUp Stack View Constraints:
stackView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
stackView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
stackView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20).isActive = true
//Add Elements
stackView.addArrangedSubview(profilePicture)
stackView.addArrangedSubview(usernameTextField)
// MARK: - Set-Up View-Elements
// SetUp ProfileIcon:
profileIcon = UIImage(named: "characteer")!
profilePicture.setImage(profileIcon, for: .normal)
profilePicture.imageView?.contentMode = .scaleAspectFill
let cornerRadius: CGFloat
cornerRadius = 75 // half of widht/height
profilePicture.layer.cornerRadius = cornerRadius
profilePicture.layer.masksToBounds = true
profilePicture.layer.borderWidth = 1
profilePicture.layer.borderColor = UIColor.white.cgColor
//profilePicture.addTarget(self, action: #selector(handleSelectedPhoto), for: .touchUpInside)
profilePicture.translatesAutoresizingMaskIntoConstraints = false
profilePicture.heightAnchor.constraint(equalToConstant: 150).isActive = true
profilePicture.widthAnchor.constraint(equalToConstant: 150).isActive = true
// SetUp UsernameTextfield:
usernameTextField.backgroundColor = .white
usernameTextField.attributedPlaceholder = NSAttributedString(string: "Username", attributes: [NSAttributedString.Key.foregroundColor: UIColor.lightGray])
usernameTextField.textAlignment = NSTextAlignment.center
usernameTextField.layer.cornerRadius = 8
usernameTextField.layer.borderWidth = 1
usernameTextField.layer.borderColor = UIColor.lightGray.cgColor
let username = usernameTextField.text
usernameTextField.translatesAutoresizingMaskIntoConstraints = false
usernameTextField.widthAnchor.constraint(equalToConstant: UIScreen.main.bounds.width-40).isActive = true
usernameTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
回答3:
I think there is a problem about your constraint.
profilePicture.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true profilePicture.topAnchor.constraint(equalTo: view.topAnchor, constant: 110).isActive = true
are trying to center of the screen but they are inside of stack view. Also you have to give a static height to stack view on this scenario.
来源：https://stackoverflow.com/questions/64552077/why-is-my-stackview-not-working-elements-are-completely-displaced