在 stackview 中隐藏视图仍然保持约束活动

Question

这段代码可以复制粘贴到新建的项目中：

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let label = createLabel()
        let imageView = createImageView()
        let stackView = UIStackView(arrangedSubviews: [imageView, label])

        stackView.axis = .vertical
        stackView.spacing = 5

        view.addSubview(stackView)
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        stackView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

        Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { (_) in
            imageView.isHidden = true
        }
    }

    func createLabel() -> UILabel {
        let label = UILabel(frame: .zero)

        label.text = "Some Text"
        label.setContentHuggingPriority(.required, for: .horizontal)
        label.setContentHuggingPriority(.required, for: .vertical)
        label.backgroundColor = .green

        return label
    }

    func createImageView() -> UIImageView {
        let imageView = UIImageView()

        imageView.backgroundColor = .red
        imageView.heightAnchor.constraint(equalToConstant: 200).isActive = true
        imageView.heightAnchor.constraint(equalTo: imageView.widthAnchor).isActive = true

        return imageView
    }
}

它是一个UILabel和一个UIImageView里面的一个UIStackView。当我隐藏 UIImageView 时，我看到 UIStackView 正确地适应了 UILabel's 高度。但是，UIStackView 不会自动适应 UILabel 的宽度。

如何使 UIStackView 调整自身大小使其仅显示可见视图/UILabel？我为 UIImageView 的高度锚定常量设置了一个变量约束，并在隐藏 UIImageView 时将其关闭，但 UILabel 由于某些奇怪的原因消失了。

Answer 1

尝试在 UIStackView 的属性检查器中将 Distribution 更改为 Fill Equally，并将 Alignment 更改为 Fill 或 center，如您所愿成为。

Answer 2

添加堆栈视图alignment

This property determines how the stack view lays out its arranged views perpendicularly to its axis. The default value is UIStackView.Alignment.fill.

stackView.alignment = .leading

Stackview 将自身调整为仅可见的 UILabel

在 stackview 中隐藏视图仍然保持约束活动

Hiding a view inside stackview still keeps constraints active

swift

uistackview