我使用自动布局在 viewDidAppear 方法中添加了一个 View 。最后 viewDidAppear 试图找到我添加的 View 高度,我得到零?
我添加的那个 View 有一个标签,该标签的高度是动态的
let viewToShowIn = self.view!
let bannerView = UIView()
bannerView.backgroundColor = UIColor.red
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
viewToShowIn.addSubview(bannerView)
bannerView.addSubview(label)
let margins = viewToShowIn.layoutMarginsGuide
bannerView.translatesAutoresizingMaskIntoConstraints = false
bannerView.leadingAnchor.constraint(equalTo: viewToShowIn.leadingAnchor, constant: 0).isActive = true
bannerView.trailingAnchor.constraint(equalTo: viewToShowIn.trailingAnchor, constant: 0).isActive = true
let bannerTopConstraint = bannerView.topAnchor.constraint(equalTo: margins.topAnchor, constant: 0)
bannerTopConstraint.isActive = true
label.font = UIFont.systemFont(ofSize: 20)
label.text = "kjafj kfj fk fjk dakjd k fdjakljf dkfjklsdjf dfsjlkj lkfsdjlkjl sjflksdjfljslf sdfljdslkjflsdjf sldfjlksj"
label.numberOfLines = 0
label.lineBreakMode = .byWordWrapping
label.textAlignment = .center
label.leadingAnchor.constraint(equalTo: bannerView.leadingAnchor, constant: 20).isActive = true
label.trailingAnchor.constraint(equalTo: bannerView.trailingAnchor, constant: -20).isActive = true
label.topAnchor.constraint(equalTo: bannerView.topAnchor, constant: 10).isActive = true
bannerView.bottomAnchor.constraint(equalTo: label.bottomAnchor, constant: 10).isActive = true
最佳答案
声明您的标签并查看为全局变量,例如
var viewToShowIn = UIView()
let bannerView = UIView()
let label = UILabel()
然后在
viewDidAppear
中设置约束或 viewDidLoad
viewToShowIn = self.view!
bannerView.backgroundColor = UIColor.red
label.translatesAutoresizingMaskIntoConstraints = false
viewToShowIn.addSubview(bannerView)
bannerView.addSubview(label)
let margins = viewToShowIn.layoutMarginsGuide
bannerView.translatesAutoresizingMaskIntoConstraints = false
bannerView.leadingAnchor.constraint(equalTo: viewToShowIn.leadingAnchor, constant: 0).isActive = true
bannerView.trailingAnchor.constraint(equalTo: viewToShowIn.trailingAnchor, constant: 0).isActive = true
let bannerTopConstraint = bannerView.topAnchor.constraint(equalTo: margins.topAnchor, constant: 0)
bannerTopConstraint.isActive = true
label.font = UIFont.systemFont(ofSize: 20)
label.text = "kjafj kfj fk fjk dakjd k fdjakljf dkfjklsdjf dfsjlkj lkfsdjlkjl sjflksdjfljslf sdfljdslkjflsdjf sldfjlksj"
label.numberOfLines = 0
label.lineBreakMode = .byWordWrapping
label.textAlignment = .center
label.leadingAnchor.constraint(equalTo: bannerView.leadingAnchor, constant: 20).isActive = true
label.trailingAnchor.constraint(equalTo: bannerView.trailingAnchor, constant: -20).isActive = true
label.topAnchor.constraint(equalTo: bannerView.topAnchor, constant: 10).isActive = true
bannerView.bottomAnchor.constraint(equalTo: label.bottomAnchor, constant: 10).isActive = true
您将在
viewWillLayoutSubviews()
中获得 View 或标签的高度或 viewDidLayoutSubviews()
方法override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
// GET YOUR HEIGHT HERE
}
关于ios - 获取自动布局添加的uiview高度,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49168680/