我试图在@IBDesignable UIView上添加渐变。模拟器中的一切都很好,但是当我在物理设备上运行它时,渐变不会填满屏幕。我在UIView扩展程序中获得了渐变代码:
extension UIView {
func gradientFrom(_ colors: [UIColor]) {
let cgColors = colors.map({return $0.cgColor})
let gradient = CAGradientLayer()
gradient.frame = self.bounds
gradient.locations = [0.0, 1.0]
gradient.colors = cgColors
self.layer.insertSublayer(gradient, at: 0)
}
}
接下来,我的UIView中以渐变为中心的代码:
@IBDesignable class MyCustomView: UIView {
var view = UIView()
// MARK: - IBOutlets
@IBOutlet weak var label: UILabel!
@IBOutlet weak var textView: UITextView!
fileprivate var gradientColors: [UIColor] = []
@IBInspectable var gradientColor0: UIColor = UIColor.flatWhite {
didSet {
gradientColors.remove(at: 0)
gradientColors.insert(gradientColor0, at: 0)
}
}
@IBInspectable var gradientColor1: UIColor = UIColor.flatWhiteDark {
didSet {
gradientColors.remove(at: 1)
gradientColors.insert(gradientColor1, at: 1)
}
}
override init(frame: CGRect) {
super.init(frame: frame)
xibSetup()
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
xibSetup()
setup()
}
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
setup()
}
func setup() {
textView.scrollRangeToVisible(NSMakeRange(0, 0))
[gradientColor0, gradientColor1].forEach({gradientColors.append($0)})
view.gradientFrom(gradientColors)
label.textColor = labelFontColor
label.backgroundColor = UIColor.clear
textView.backgroundColor = UIColor.clear
textView.textColor = textViewFontColor
}
// MARK: - Nib handlers
fileprivate func xibSetup() {
view = loadViewFromNib()
view.frame = bounds
view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
addSubview(view)
}
fileprivate func loadViewFromNib() -> UIView {
let bundle = Bundle(for: type(of: self))
let nib = UINib(nibName: "AttributionView", bundle: bundle)
let view = nib.instantiate(withOwner: self, options: nil).first as! UIView
return view
}
public func applyBackgroundGradient() {
view.gradientFrom(gradientColors)
}
func resizeView() {
textView.sizeToFit()
textView.scrollRangeToVisible(NSMakeRange(0, 0))
}
}
在MyViewController上,我添加了一个UIView,将其子类设置为MyCustomView。界面构建器填充,但是当我在物理设备上运行它时,MyCustomView中的渐变不会填满整个屏幕。
我尝试从applyBackgroundGradient
MyViewController
viewDidLoad
,viewDidLayoutSubviews
,viewDidAppear
运行{{1}},但这些似乎都没有完成任务。
任何建议:如何解决这个问题非常感谢。谢谢你的阅读。
答案 0 :(得分:1)
尝试替换
gradient.frame = self.bounds
带
gradient.frame.size = self.frame.size
gradient.frame.origin = CGPoint(x: 0.0, y: 0.0)
你绝对应该把它称为
var didLayoutSubviews = false
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if !self.didLayoutSubviews {
self.didLayoutSubviews = true
//apply gradient
//you can also try to execute drawing inside `DispatchQueue.main.async {}`
}
}
OP的附录:
我的问题的一部分源自我didSet
调用渐变的颜色。我没有在didSet中设置数组,而是将代码用于填充gradientColors
数组到applyBackgroundGradient
方法。
@IBInspectable var gradientColor0: UIColor = UIColor.flatWhite {
didSet {
applyBackgroundGradient()
}
}
@IBInspectable var gradientColor1: UIColor = UIColor.flatWhiteDark {
didSet {
applyBackgroundGradient()
}
}
... MyCustomView
上的渐变代码如下所示:
public func applyBackgroundGradient() {
gradientColors = [gradientColor0, gradientColor1]
self.view.gradientFrom(gradientColors)
}