我正在尝试使用仅以编程方式创建的 UI 开发应用程序。我想创建一个简单的视图，它是一个 UIScrollView（当键盘出现时能够滚动视图）和一个容器视图（UIView），我们可以在其中找到一个按钮。
我正在使用 PureLayout 来简化约束的设置，swift 4，Xcode 9.2 beta
在这个视图的类下面
class SimpleView: UIScrollView {
var containerView: UIView!
var signInButton: UIButton!
var signInLabel: UILabel!
var screenSize: CGSize = CGSize.zero
var shouldSetupConstraints = true
override init(frame: CGRect) {
super.init(frame: frame)
self.screenSize = frame.size
self.containerView = UIView(frame: CGRect.zero)
self.signInButton = UIButton(frame: CGRect.zero)
self.signInLabel = UILabel(frame: CGRect.zero)
self.addSubview(self.containerView)
self.containerView.addSubview(self.signInButton)
self.signInButton.addSubview(self.signInLabel)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func updateConstraints() {
if(shouldSetupConstraints) {
self.layoutSignInButton()
self.layoutSignInLabel()
shouldSetupConstraints = false
}
super.updateConstraints()
}
private func layoutContainerView() {
self.containerView.autoPinEdgesToSuperviewEdges()
self.containerView.backgroundColor = UIColor.yellow
}
private func layoutSignInButton() {
self.signInButton.autoPinEdge(toSuperviewEdge: .right)
self.signInButton.autoPinEdge(toSuperviewEdge: .left)
self.signInButton.autoPinEdge(toSuperviewEdge: .top)
self.signInButton.autoSetDimension(.height, toSize: 55.0)
self.signInButton.backgroundColor = UIColor(hex: "#FD9FA2")
}
private func layoutSignInLabel() {
self.signInLabel.autoPinEdgesToSuperviewEdges()
self.signInLabel.shadowColor = UIColor(hex: "#9A615E")
self.signInLabel.shadowOffset = CGSize(width: 0.0, height: 2)
self.signInLabel.text = NSLocalizedString("SIGN IN", comment: "")
self.signInLabel.textAlignment = .center
self.signInLabel.textColor = UIColor.white
self.signInLabel.font = UIFont.boldSystemFont(ofSize: 15.0)
self.signInLabel.backgroundColor = UIColor.clear
}
}
下面是嵌入前一个视图的 UIViewController 子类的代码
class SignInViewController: UIViewController {
var simpleView: SimpleView!
override func viewDidLoad() {
super.viewDidLoad()
self.simpleView = SimpleView(frame: self.view.bounds) // with SimpleView(frame: self.view.frame) has the same behaviour
self.view.addSubview(self.simpleView)
self.simpleView.autoPinEdgesToSuperviewEdges()
self.navigationController?.navigationBar.isHidden = true
}
}
不幸的是，结果不是预期的：见下文
我错过了什么？缺少不同的点： - 按钮的位置很奇怪（按钮和按钮的顶部/左侧之间的空间部分隐藏在屏幕之外） - 容器视图不可见（backgroundColor = UIColor.yellow 无效）
提前谢谢你！
//////////////////////////// 编辑 ///////////////////// ///////////
下面是使用 UIView 而不是 UIScrollView 的完全相同代码的屏幕截图
Class SimpleView: UIView {
