我正在尝试以编程方式创建UIStackView,但它根本没有显示。
为了测试,我创建了2个小UIView
个,我添加到UIStackView
。
UIStackView
layoutIfNeeded
layoutSubviews
但没有任何效果。
import UIKit
class ViewController: UIViewController {
var contentStack = UIStackView()
@IBOutlet weak var mainScroll: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
contentStack.backgroundColor = #colorLiteral(red: 0.05882352963, green: 0.180392161, blue: 0.2470588237, alpha: 1)
contentStack.axis = .vertical
contentStack.spacing = 0
contentStack.alignment = .top
contentStack.distribution = .equalSpacing
let a_view = UIView(frame: CGRect(x: 0, y: 0, width: 20, height: 30))
a_view.backgroundColor = #colorLiteral(red: 0.4666666687, green: 0.7647058964, blue: 0.2666666806, alpha: 1)
contentStack.addArrangedSubview(a_view)
let b_view = UIView(frame: CGRect(x: 0, y: 0, width: 50, height: 40))
b_view.backgroundColor = #colorLiteral(red: 0.9607843161, green: 0.7058823705, blue: 0.200000003, alpha: 1)
contentStack.addArrangedSubview(b_view)
mainScroll.addSubview(contentStack)
contentStack.topAnchor.constraint(equalTo: mainScroll.topAnchor).isActive = true
contentStack.leftAnchor.constraint(equalTo: mainScroll.leftAnchor).isActive = true
contentStack.bottomAnchor.constraint(equalTo: mainScroll.bottomAnchor).isActive = true
contentStack.rightAnchor.constraint(equalTo: mainScroll.rightAnchor).isActive = true
mainScroll.contentSize = CGSize(width: self.view.frame.width, height: contentStack.frame.height)
print("Stack Content Size: (\(contentStack.frame.width), \(contentStack.frame.height))");
}
}
阅读文档后,我假设UIStackView
的身高和高度宽度都适应视图添加后包含堆栈视图大小的元素,它是Stack Content Size: (0.0, 0.0)
?
答案 0 :(得分:6)
尝试设置a_view和b_view的约束,如下所示
let a_view = UIView()
a_view.translatesAutoresizingMaskIntoConstraints = false
a_view.heightAnchor.constraint(equalToConstant: 30).isActive = true
a_view.widthAnchor.constraint(equalToConstant: 30).isActive = true
堆栈视图使用内在内容大小,因此使用布局约束来定义视图的维度。
如果这不起作用,那么我怀疑滚动视图约束可能存在一些问题。