视图旋转时视图尺寸变小

Question

我有意见。旋转时，视图尺寸变小。你能看看我附上的照片吗？

@IBAction func buttonForNewView(_ sender: Any) {
    self.view.addSubview(customvView)
    customvView.layer.cornerRadius = 15
    customvView.backgroundColor = .gray
    customvView.translatesAutoresizingMaskIntoConstraints = false
    customvView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: view.frame.size.height*0.1).isActive = true
    customvView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: view.frame.size.width*0.1).isActive = true
    customvView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -view.frame.size.width*0.1).isActive = true
    customvView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant:-view.frame.size.height*0.1).isActive = true
}

Answer 1

检查此代码。

    let val = view.frame.size.height*0.1

    self.view.addSubview(customvView)
    customvView.layer.cornerRadius = 15
    customvView.backgroundColor = .gray
    customvView.translatesAutoresizingMaskIntoConstraints = false
    customvView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: val).isActive = true
    customvView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: val).isActive = true
    customvView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -val).isActive = true
    customvView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant:-val).isActive = true

Answer 2

旋转设备时不会重新计算约束。
这将约束计算分解为一个单独的函数。然后它会覆盖 traitCollectionDidChange()。当特征集合发生变化时，它会删除旧的约束（以防止自动布局混淆）并重新应用新的约束。

    import UIKit

class ViewController: UIViewController {

    var customvView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        customvView = UIView()
        // Do any additional setup after loading the view.
    }

    func constrainCustomvView() {
        customvView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: view.frame.size.height*0.1).isActive = true
        customvView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: view.frame.size.width*0.1).isActive = true
        customvView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -view.frame.size.width*0.1).isActive = true
        customvView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant:-view.frame.size.height*0.1).isActive = true
    }

    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        if view.subviews.contains(customvView) { // for the case that the traits change before the view is created

            // remove the existing constraits, or autolayout will have to choose between two and it will choose poorly
            for constraint in view.constraints {
                if let first = constraint.firstItem as? UIView, first == customvView {
                    view.removeConstraint(constraint)
                }
                
                if let second = constraint.secondItem as? UIView, second == customvView {
                    view.removeConstraint(constraint)
                }
            }
            constrainCustomvView()
        }
    }
    
    @IBAction func CustomButton(_ sender: Any) {
        self.view.addSubview(customvView)
        customvView.layer.cornerRadius = 15
        customvView.backgroundColor = .gray
        customvView.translatesAutoresizingMaskIntoConstraints = false
        constrainCustomvView()
    }
}

视图旋转时视图尺寸变小

the view size gets smaller when the view is rotated

ios

autolayout

swift