如何防止一个 UIView 被另一个 UIView 隐藏?
How do I prevent one UIView from being hidden by another UIView?
我正在使用 UIViews
创建一个自定义的、可重复使用的分段控制器,但我遇到了重叠视图的问题。目前看起来像这样:
您可以看到蓝色选择器在 按钮下方,但我希望它位于 底部并且有四个像素高.为此,我有:
let numberOfButtons = CGFloat(buttonTitles.count)
let selectorWidth = frame.width / numberOfButtons
let selectorYPosition = frame.height - 3 <--- This cause it to be hidden behind the button
selector = UIView(frame: CGRect(x: 0, y: selectorYPosition, width: selectorWidth, height: 4))
selector.layer.cornerRadius = 0
selector.backgroundColor = selectorColor
addSubview(selector)
bringSubviewToFront(selector) <--- I thought this would work but it does nothing
这导致选择器 UIView
隐藏在段 UIView
后面(我将 Y 位置设置为 - 3 这样您就可以看到它是如何被掩盖的。我实际上希望它是 - 4,但这使它完全消失了):
我认为使用 bringSubviewToFront()
会将其置于段 UIView
之前,但它似乎没有任何作用。我查看了 Apple View Programming Guide 和许多 SO 线程,但找不到答案。
谁能帮我看看我错过了什么?
完整代码:
class CustomSegmentedControl: UIControl {
var buttons = [UIButton]()
var selector: UIView!
var selectedButtonIndex = 0
var borderWidth: CGFloat = 0 {
didSet {
layer.borderWidth = borderWidth
}
}
var borderColor: UIColor = UIColor.black {
didSet {
layer.borderColor = borderColor.cgColor
}
}
var separatorBorderColor: UIColor = UIColor.lightGray {
didSet {
}
}
var commaSeparatedTitles: String = "" {
didSet {
updateView()
}
}
var textColor: UIColor = .lightGray {
didSet {
updateView()
}
}
var selectorColor: UIColor = .blue {
didSet {
updateView()
}
}
var selectorTextColor: UIColor = .black {
didSet {
updateView()
}
}
func updateView() {
buttons.removeAll()
subviews.forEach { [=11=].removeFromSuperview() }
// create buttons
let buttonTitles = commaSeparatedTitles.components(separatedBy: ",")
for buttonTitle in buttonTitles {
let button = UIButton(type: .system)
button.setTitle(buttonTitle, for: .normal)
button.setTitleColor(textColor, for: .normal)
button.backgroundColor = UIColor.white
button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
buttons.append(button)
}
// make first button selected
buttons[0].setTitleColor(selectorTextColor, for: .normal)
let numberOfButtons = CGFloat(buttonTitles.count)
let selectorWidth = frame.width / numberOfButtons
let selectorYPosition = frame.height - 3
selector = UIView(frame: CGRect(x: 0, y: selectorYPosition, width: selectorWidth, height: 4))
selector.layer.cornerRadius = 0
selector.backgroundColor = selectorColor
addSubview(selector)
bringSubviewToFront(selector)
let stackView = UIStackView(arrangedSubviews: buttons)
stackView.axis = .horizontal
stackView.alignment = .fill
stackView.distribution = .fillEqually
addSubview(stackView)
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
stackView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
stackView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
}
@objc func buttonTapped(button: UIButton) {
for (buttonIndex, btn) in buttons.enumerated() {
btn.setTitleColor(textColor, for: .normal)
if btn == button {
let numberOfButtons = CGFloat(buttons.count)
let selectorStartPosition = frame.width / numberOfButtons * CGFloat(buttonIndex)
UIView.animate(withDuration: 0.3, animations: { self.selector.frame.origin.x = selectorStartPosition })
btn.setTitleColor(selectorTextColor, for: .normal)
}
}
sendActions(for: .valueChanged)
}
}
你正在用 stackView 掩盖你的 selector
。
您需要做的:
bringSubviewToFront(selector)
添加完所有视图后。将该行移动到 updateView()
.
的底部
我正在使用 UIViews
创建一个自定义的、可重复使用的分段控制器,但我遇到了重叠视图的问题。目前看起来像这样:
您可以看到蓝色选择器在 按钮下方,但我希望它位于 底部并且有四个像素高.为此,我有:
let numberOfButtons = CGFloat(buttonTitles.count)
let selectorWidth = frame.width / numberOfButtons
let selectorYPosition = frame.height - 3 <--- This cause it to be hidden behind the button
selector = UIView(frame: CGRect(x: 0, y: selectorYPosition, width: selectorWidth, height: 4))
selector.layer.cornerRadius = 0
selector.backgroundColor = selectorColor
addSubview(selector)
bringSubviewToFront(selector) <--- I thought this would work but it does nothing
这导致选择器 UIView
隐藏在段 UIView
后面(我将 Y 位置设置为 - 3 这样您就可以看到它是如何被掩盖的。我实际上希望它是 - 4,但这使它完全消失了):
我认为使用 bringSubviewToFront()
会将其置于段 UIView
之前,但它似乎没有任何作用。我查看了 Apple View Programming Guide 和许多 SO 线程,但找不到答案。
谁能帮我看看我错过了什么?
完整代码:
class CustomSegmentedControl: UIControl {
var buttons = [UIButton]()
var selector: UIView!
var selectedButtonIndex = 0
var borderWidth: CGFloat = 0 {
didSet {
layer.borderWidth = borderWidth
}
}
var borderColor: UIColor = UIColor.black {
didSet {
layer.borderColor = borderColor.cgColor
}
}
var separatorBorderColor: UIColor = UIColor.lightGray {
didSet {
}
}
var commaSeparatedTitles: String = "" {
didSet {
updateView()
}
}
var textColor: UIColor = .lightGray {
didSet {
updateView()
}
}
var selectorColor: UIColor = .blue {
didSet {
updateView()
}
}
var selectorTextColor: UIColor = .black {
didSet {
updateView()
}
}
func updateView() {
buttons.removeAll()
subviews.forEach { [=11=].removeFromSuperview() }
// create buttons
let buttonTitles = commaSeparatedTitles.components(separatedBy: ",")
for buttonTitle in buttonTitles {
let button = UIButton(type: .system)
button.setTitle(buttonTitle, for: .normal)
button.setTitleColor(textColor, for: .normal)
button.backgroundColor = UIColor.white
button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
buttons.append(button)
}
// make first button selected
buttons[0].setTitleColor(selectorTextColor, for: .normal)
let numberOfButtons = CGFloat(buttonTitles.count)
let selectorWidth = frame.width / numberOfButtons
let selectorYPosition = frame.height - 3
selector = UIView(frame: CGRect(x: 0, y: selectorYPosition, width: selectorWidth, height: 4))
selector.layer.cornerRadius = 0
selector.backgroundColor = selectorColor
addSubview(selector)
bringSubviewToFront(selector)
let stackView = UIStackView(arrangedSubviews: buttons)
stackView.axis = .horizontal
stackView.alignment = .fill
stackView.distribution = .fillEqually
addSubview(stackView)
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
stackView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
stackView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
}
@objc func buttonTapped(button: UIButton) {
for (buttonIndex, btn) in buttons.enumerated() {
btn.setTitleColor(textColor, for: .normal)
if btn == button {
let numberOfButtons = CGFloat(buttons.count)
let selectorStartPosition = frame.width / numberOfButtons * CGFloat(buttonIndex)
UIView.animate(withDuration: 0.3, animations: { self.selector.frame.origin.x = selectorStartPosition })
btn.setTitleColor(selectorTextColor, for: .normal)
}
}
sendActions(for: .valueChanged)
}
}
你正在用 stackView 掩盖你的 selector
。
您需要做的:
bringSubviewToFront(selector)
添加完所有视图后。将该行移动到 updateView()
.