所以我有一个 UIButton，我将其中的标题设置为长度动态的字符串。我希望 titleLabel 的宽度是屏幕宽度的一半。我尝试过使用 .sizeToFit() 但这会导致按钮在将约束应用于 titleLabel 之前使用 CGSize。我尝试使用 .sizeThatFits(button.titleLabel?.intrinsicContentSize) 但这也不起作用。我认为下面的重要函数是 init() 和 PresentCallout()，但我展示整个类只是为了更完整的理解。我正在玩的类(class)看起来像:
class CustomCalloutView: UIView, MGLCalloutView {
var representedObject: MGLAnnotation
// Allow the callout to remain open during panning.
let dismissesAutomatically: Bool = false
let isAnchoredToAnnotation: Bool = true
// https://github.com/mapbox/mapbox-gl-native/issues/9228
override var center: CGPoint {
set {
var newCenter = newValue
newCenter.y -= bounds.midY
super.center = newCenter
}
get {
return super.center
}
}
lazy var leftAccessoryView = UIView() /* unused */
lazy var rightAccessoryView = UIView() /* unused */
weak var delegate: MGLCalloutViewDelegate?
let tipHeight: CGFloat = 10.0
let tipWidth: CGFloat = 20.0
let mainBody: UIButton
required init(representedObject: MGLAnnotation) {
self.representedObject = representedObject
self.mainBody = UIButton(type: .system)
super.init(frame: .zero)
backgroundColor = .clear
mainBody.backgroundColor = .white
mainBody.tintColor = .black
mainBody.contentEdgeInsets = UIEdgeInsets(top: 10.0, left: 10.0, bottom: 10.0, right: 10.0)
mainBody.layer.cornerRadius = 4.0
addSubview(mainBody)
// I thought this would work, but it doesn't.
// mainBody.translatesAutoresizingMaskIntoConstraints = false
// mainBody.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
// mainBody.leftAnchor.constraint(equalTo: self.rightAnchor).isActive = true
// mainBody.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
// mainBody.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
}
required init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
// MARK: - MGLCalloutView API
func presentCallout(from rect: CGRect, in view: UIView, constrainedTo constrainedRect: CGRect, animated: Bool) {
delegate?.calloutViewWillAppear?(self)
view.addSubview(self)
// Prepare title label.
mainBody.setTitle(representedObject.title!, for: .normal)
mainBody.titleLabel?.lineBreakMode = .byWordWrapping
mainBody.titleLabel?.numberOfLines = 0
mainBody.sizeToFit()
if isCalloutTappable() {
// Handle taps and eventually try to send them to the delegate (usually the map view).
mainBody.addTarget(self, action: #selector(CustomCalloutView.calloutTapped), for: .touchUpInside)
} else {
// Disable tapping and highlighting.
mainBody.isUserInteractionEnabled = false
}
// Prepare our frame, adding extra space at the bottom for the tip.
let frameWidth = mainBody.bounds.size.width
let frameHeight = mainBody.bounds.size.height + tipHeight
let frameOriginX = rect.origin.x + (rect.size.width/2.0) - (frameWidth/2.0)
let frameOriginY = rect.origin.y - frameHeight
frame = CGRect(x: frameOriginX, y: frameOriginY, width: frameWidth, height: frameHeight)
if animated {
alpha = 0
UIView.animate(withDuration: 0.2) { [weak self] in
guard let strongSelf = self else {
return
}
strongSelf.alpha = 1
strongSelf.delegate?.calloutViewDidAppear?(strongSelf)
}
} else {
delegate?.calloutViewDidAppear?(self)
}
}
func dismissCallout(animated: Bool) {
if (superview != nil) {
if animated {
UIView.animate(withDuration: 0.2, animations: { [weak self] in
self?.alpha = 0
}, completion: { [weak self] _ in
self?.removeFromSuperview()
})
} else {
removeFromSuperview()
}
}
}
// MARK: - Callout interaction handlers
func isCalloutTappable() -> Bool {
if let delegate = delegate {
if delegate.responds(to: #selector(MGLCalloutViewDelegate.calloutViewShouldHighlight)) {
return delegate.calloutViewShouldHighlight!(self)
}
}
return false
}
@objc func calloutTapped() {
if isCalloutTappable() && delegate!.responds(to: #selector(MGLCalloutViewDelegate.calloutViewTapped)) {
delegate!.calloutViewTapped!(self)
}
}
// MARK: - Custom view styling
override func draw(_ rect: CGRect) {
// Draw the pointed tip at the bottom.
let fillColor: UIColor = .white
let tipLeft = rect.origin.x + (rect.size.width / 2.0) - (tipWidth / 2.0)
let tipBottom = CGPoint(x: rect.origin.x + (rect.size.width / 2.0), y: rect.origin.y + rect.size.height)
let heightWithoutTip = rect.size.height - tipHeight - 1
let currentContext = UIGraphicsGetCurrentContext()!
let tipPath = CGMutablePath()
tipPath.move(to: CGPoint(x: tipLeft, y: heightWithoutTip))
tipPath.addLine(to: CGPoint(x: tipBottom.x, y: tipBottom.y))
tipPath.addLine(to: CGPoint(x: tipLeft + tipWidth, y: heightWithoutTip))
tipPath.closeSubpath()
fillColor.setFill()
currentContext.addPath(tipPath)
currentContext.fillPath()
}
}
这就是短标题和长标题的样子。当标题太长时，我希望文本换行并且气泡获得更高的高度。正如您在下面的图像集中看到的，第一个“短名称”可以很好地用作 map 注释气泡。但是，当名称变得超长时，它只会将气泡扩大到超出屏幕的程度。
非常感谢有关如何修复的任何帮助。谢谢!
最佳答案
要在 UIButton 中启用多行自动换行，您需要创建自己的按钮子类。
例如:
class MultilineTitleButton: UIButton {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
func commonInit() -> Void {
self.titleLabel?.numberOfLines = 0
self.titleLabel?.textAlignment = .center
self.setContentHuggingPriority(UILayoutPriority.defaultLow + 1, for: .vertical)
self.setContentHuggingPriority(UILayoutPriority.defaultLow + 1, for: .horizontal)
}
override var intrinsicContentSize: CGSize {
let size = self.titleLabel!.intrinsicContentSize
return CGSize(width: size.width + contentEdgeInsets.left + contentEdgeInsets.right, height: size.height + contentEdgeInsets.top + contentEdgeInsets.bottom)
}
override func layoutSubviews() {
super.layoutSubviews()
titleLabel?.preferredMaxLayoutWidth = self.titleLabel!.frame.size.width
}
}
该按钮会将标题包装到多行中，与自动布局/约束配合。
我没有任何使用 MapBox 的项目，但这里有一个使用 CustomCalloutView 的修改版本的示例。我注释掉了任何 MapBox 特定代码。您也许能够取消注释这些行并按原样使用:
class CustomCalloutView: UIView { //}, MGLCalloutView {
//var representedObject: MGLAnnotation
var repTitle: String = ""
// Allow the callout to remain open during panning.
let dismissesAutomatically: Bool = false
let isAnchoredToAnnotation: Bool = true
// https://github.com/mapbox/mapbox-gl-native/issues/9228
// NOTE: this causes a vertical shift when NOT using MapBox
// override var center: CGPoint {
// set {
// var newCenter = newValue
// newCenter.y -= bounds.midY
// super.center = newCenter
// }
// get {
// return super.center
// }
// }
lazy var leftAccessoryView = UIView() /* unused */
lazy var rightAccessoryView = UIView() /* unused */
//weak var delegate: MGLCalloutViewDelegate?
let tipHeight: CGFloat = 10.0
let tipWidth: CGFloat = 20.0
let mainBody: UIButton
var anchorView: UIView!
override func willMove(toSuperview newSuperview: UIView?) {
if newSuperview == nil {
anchorView.removeFromSuperview()
}
}
//required init(representedObject: MGLAnnotation) {
required init(title: String) {
self.repTitle = title
self.mainBody = MultilineTitleButton()
super.init(frame: .zero)
backgroundColor = .clear
mainBody.backgroundColor = .white
mainBody.setTitleColor(.black, for: [])
mainBody.tintColor = .black
mainBody.contentEdgeInsets = UIEdgeInsets(top: 10.0, left: 10.0, bottom: 10.0, right: 10.0)
mainBody.layer.cornerRadius = 4.0
addSubview(mainBody)
mainBody.translatesAutoresizingMaskIntoConstraints = false
let padding: CGFloat = 8.0
NSLayoutConstraint.activate([
mainBody.topAnchor.constraint(equalTo: self.topAnchor, constant: padding),
mainBody.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: padding),
mainBody.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -padding),
mainBody.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -padding),
])
}
required init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
// MARK: - MGLCalloutView API
func presentCallout(from rect: CGRect, in view: UIView, constrainedTo constrainedRect: CGRect, animated: Bool) {
//delegate?.calloutViewWillAppear?(self)
// since we'll be using auto-layout for the mutli-line button
// we'll add an "anchor view" to the superview
// it will be removed when self is removed
anchorView = UIView(frame: rect)
anchorView.isUserInteractionEnabled = false
anchorView.backgroundColor = .clear
view.addSubview(anchorView)
view.addSubview(self)
// Prepare title label.
//mainBody.setTitle(representedObject.title!, for: .normal)
mainBody.setTitle(self.repTitle, for: .normal)
// if isCalloutTappable() {
// // Handle taps and eventually try to send them to the delegate (usually the map view).
// mainBody.addTarget(self, action: #selector(CustomCalloutView.calloutTapped), for: .touchUpInside)
// } else {
// // Disable tapping and highlighting.
// mainBody.isUserInteractionEnabled = false
// }
self.translatesAutoresizingMaskIntoConstraints = false
anchorView.autoresizingMask = [.flexibleTopMargin, .flexibleLeftMargin, .flexibleRightMargin, .flexibleBottomMargin]
NSLayoutConstraint.activate([
self.centerXAnchor.constraint(equalTo: anchorView.centerXAnchor),
self.bottomAnchor.constraint(equalTo: anchorView.topAnchor),
self.widthAnchor.constraint(lessThanOrEqualToConstant: constrainedRect.width),
])
if animated {
alpha = 0
UIView.animate(withDuration: 0.2) { [weak self] in
guard let strongSelf = self else {
return
}
strongSelf.alpha = 1
//strongSelf.delegate?.calloutViewDidAppear?(strongSelf)
}
} else {
//delegate?.calloutViewDidAppear?(self)
}
}
func dismissCallout(animated: Bool) {
if (superview != nil) {
if animated {
UIView.animate(withDuration: 0.2, animations: { [weak self] in
self?.alpha = 0
}, completion: { [weak self] _ in
self?.removeFromSuperview()
})
} else {
removeFromSuperview()
}
}
}
// MARK: - Callout interaction handlers
// func isCalloutTappable() -> Bool {
// if let delegate = delegate {
// if delegate.responds(to: #selector(MGLCalloutViewDelegate.calloutViewShouldHighlight)) {
// return delegate.calloutViewShouldHighlight!(self)
// }
// }
// return false
// }
//
// @objc func calloutTapped() {
// if isCalloutTappable() && delegate!.responds(to: #selector(MGLCalloutViewDelegate.calloutViewTapped)) {
// delegate!.calloutViewTapped!(self)
// }
// }
// MARK: - Custom view styling
override func draw(_ rect: CGRect) {
print(#function)
// Draw the pointed tip at the bottom.
let fillColor: UIColor = .red
let tipLeft = rect.origin.x + (rect.size.width / 2.0) - (tipWidth / 2.0)
let tipBottom = CGPoint(x: rect.origin.x + (rect.size.width / 2.0), y: rect.origin.y + rect.size.height)
let heightWithoutTip = rect.size.height - tipHeight - 1
let currentContext = UIGraphicsGetCurrentContext()!
let tipPath = CGMutablePath()
tipPath.move(to: CGPoint(x: tipLeft, y: heightWithoutTip))
tipPath.addLine(to: CGPoint(x: tipBottom.x, y: tipBottom.y))
tipPath.addLine(to: CGPoint(x: tipLeft + tipWidth, y: heightWithoutTip))
tipPath.closeSubpath()
fillColor.setFill()
currentContext.addPath(tipPath)
currentContext.fillPath()
}
}
这是一个示例 View Controller ，显示具有各种长度标题的“Callout View”，限制为 View 宽度的 70%:
class CalloutTestVC: UIViewController {
let sampleTitles: [String] = [
"Short Title",
"Slightly Longer Title",
"A ridiculously long title that will need to wrap!",
]
var idx: Int = -1
let tapView = UIView()
var ccv: CustomCalloutView!
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor(red: 0.8939146399, green: 0.8417750597, blue: 0.7458069921, alpha: 1)
tapView.backgroundColor = .systemBlue
tapView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(tapView)
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
tapView.centerYAnchor.constraint(equalTo: g.centerYAnchor),
tapView.centerXAnchor.constraint(equalTo: g.centerXAnchor),
tapView.widthAnchor.constraint(equalToConstant: 60),
tapView.heightAnchor.constraint(equalTo: tapView.widthAnchor),
])
// tap the Blue View to cycle through Sample Titles for the Callout View
// using the Blue view as the "anchor rect"
let t = UITapGestureRecognizer(target: self, action: #selector(gotTap))
tapView.addGestureRecognizer(t)
}
@objc func gotTap() -> Void {
if ccv != nil {
ccv.removeFromSuperview()
}
// increment sampleTitles array index
// to cycle through the strings
idx += 1
let validIdx = idx % sampleTitles.count
let str = sampleTitles[validIdx]
// create a new Callout view
ccv = CustomCalloutView(title: str)
// to restrict the "callout view" width to less-than 1/2 the screen width
// use view.width * 0.5 for the constrainedTo width
// may look better restricting it to 70%
ccv.presentCallout(from: tapView.frame, in: self.view, constrainedTo: CGRect(x: 0, y: 0, width: view.frame.size.width * 0.7, height: 100), animated: false)
}
}
看起来像这样:
关于swift - 根据 titleLabel 的长度调整 UIButton 的大小，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/69712171/