Question

在MainVC中，我试图将UIView限制在顶部，左侧，右侧，并且高度为80。现在，我的视图是全屏显示。我该如何修正我的代码以使其具有合适的大小？

//变量 var topViewCons：[NSLayoutConstraint] = []

// Constants
let topGradient = RadialGradientLayer()
let topMainView = UIView()
// MainVC Top View Constraints
topMainView.translatesAutoresizingMaskIntoConstraints = false
topGradient.frame = view.bounds
topMainView.layer.addSublayer(topGradient)
self.view.addSubview(topMainView)

let topConstraint = topMainView.topAnchor.constraint(equalTo: self.view.topAnchor)
let leftConstraint = topMainView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor)
let rightConstraint = topMainView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor)
let topViewHeight = topMainView.heightAnchor.constraint(equalToConstant: 80)
NSLayoutConstraint.activate([topConstraint, leftConstraint, rightConstraint, topViewHeight])

Answer 1

不是全屏，渐变是

topGradient.frame = view.bounds  // here you make it's frame to screen bounds 
topMainView.layer.addSublayer(topGradient)

所以您需要设置

topMainView.clipsToBounds = true

OR

override func viewDidLayoutSubviews() {
  super.viewDidLayoutSubviews()
  topGradient.frame = topMainView.bounds
}

此外，您也可以不使用let来直接执行

NSLayoutConstraint.activate([
      topMainView.topAnchor.constraint(equalTo: self.view.topAnchor),
      topMainView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
      topMainView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
      topMainView.heightAnchor.constraint(equalToConstant: 80)
])

如何使HeightAnchor正常工作？

1 个答案: