某些用户可能会将“按钮形状”开关设置为打开。 (设置 -> 辅助功能 -> 显示和文字大小 -> 按钮形状)
这会导致按钮标题自动带有下划线。在某些情况下这很糟糕，例如这个屏幕截图:
是否可以通过编程将其覆盖为“关闭”？我使用 Swift。
提前致谢。
最佳答案
这是一个使用 .setAttributedTitle() 删除 辅助功能 -> 按钮形状 应用的下划线的简单示例。
请注意，这只是快速拼凑在一起的——我还没有对其进行测试，所以不要将其视为“生产”代码。另请注意，代码非常“显示如何做到这一点”，而不是“这是一个好方法做到这一点” 。
class RoundButton: UIButton {
override func layoutSubviews() {
super.layoutSubviews()
layer.cornerRadius = bounds.height * 0.5
}
}
class ButtonShapesViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor(red: 54.0 / 255.0, green: 15.0 / 255.0, blue: 30.0 / 255.0, alpha: 1.0)
// just for easy layout / quick testing
// add a vertical stackView holding two horizontal stackViews for two rows of buttons
let svTopRow = UIStackView()
svTopRow.axis = .horizontal
svTopRow.alignment = .fill
svTopRow.distribution = .fill
svTopRow.spacing = 8
svTopRow.translatesAutoresizingMaskIntoConstraints = false
let svBotRow = UIStackView()
svBotRow.axis = .horizontal
svBotRow.alignment = .fill
svBotRow.distribution = .fill
svBotRow.spacing = 8
svBotRow.translatesAutoresizingMaskIntoConstraints = false
let svRows = UIStackView()
svRows.axis = .vertical
svRows.alignment = .fill
svRows.distribution = .fill
svRows.spacing = 8
svRows.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(svRows)
svRows.addArrangedSubview(svTopRow)
svRows.addArrangedSubview(svBotRow)
NSLayoutConstraint.activate([
svRows.centerXAnchor.constraint(equalTo: view.centerXAnchor),
svRows.centerYAnchor.constraint(equalTo: view.centerYAnchor),
])
// fill "row" stackViews each with 4 buttons
[svTopRow, svBotRow].forEach {
sv in
["7", "8", "9", "÷"].forEach {
title in
let btn = RoundButton()
btn.backgroundColor = UIColor(red: 201.0 / 255.0, green: 59.0 / 255.0, blue: 114.0 / 255.0, alpha: 1.0)
btn.titleLabel?.font = UIFont.systemFont(ofSize: 28.0)
btn.setTitleColor(.white, for: .normal)
btn.setTitleColor(.lightGray, for: .highlighted)
btn.setTitle(title, for: .normal)
btn.widthAnchor.constraint(equalToConstant: 54.0).isActive = true
btn.heightAnchor.constraint(equalTo: btn.widthAnchor).isActive = true
sv.addArrangedSubview(btn)
}
}
// now, let's disable the "Button Shapes" underlining for the bottom row
svBotRow.arrangedSubviews.forEach {
// just for sanity
guard let btn = $0 as? UIButton, let title = btn.currentTitle, let curAttText = btn.titleLabel?.attributedText else {
fatalError("Not a button!")
}
// normal state
let mutAttTextNorm = NSMutableAttributedString(attributedString: curAttText)
mutAttTextNorm.addAttribute(NSAttributedString.Key.underlineStyle, value: 0, range: NSRange(location: 0, length: title.count))
btn.setAttributedTitle(mutAttTextNorm, for: .normal)
// highlighted state
let mutAttTextHigh = NSMutableAttributedString(attributedString: curAttText)
mutAttTextHigh.addAttribute(NSAttributedString.Key.underlineStyle, value: 0, range: NSRange(location: 0, length: title.count))
mutAttTextHigh.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.lightGray, range: NSRange(location: 0, length: title.count))
btn.setAttributedTitle(mutAttTextHigh, for: .highlighted)
}
}
}
结果(底行已禁用下划线):
关于是否实际执行此操作的哲学讨论超出了 Stack Overflow 的范围。正如您在评论中提到的，计算器按钮不显示下划线...日历应用程序“圆形日期按钮”、搜索按钮和“+”添加按钮也不显示下划线。
编辑
这是另一个示例 - 按钮的“5 x 5 网格”会根据设备旋转调整大小。
按钮点击只是将其标题附加到“inputLabel” - 不进行任何计算。除了“退格键”按钮外，它可以在“⌫”未选中状态和“⌦”选中状态之间切换。
class RoundButton: UIButton {
override func layoutSubviews() {
super.layoutSubviews()
layer.cornerRadius = bounds.height * 0.5
}
}
struct CalcButton {
var normalTitle: String = ""
var selectedTitle: String = ""
var foreColor: UIColor = .white
var backColor: UIColor = .black
}
class ButtonShapesViewController: UIViewController {
let inputLabel: UILabel = {
let v = UILabel()
v.textColor = .white
v.textAlignment = .right
v.text = "0"
v.font = UIFont.systemFont(ofSize: 28.0)
v.translatesAutoresizingMaskIntoConstraints = false
v.setContentHuggingPriority(.required, for: .vertical)
v.setContentCompressionResistancePriority(.required, for: .vertical)
return v
}()
var normAttributes: [NSAttributedString.Key: Any] = [:]
var highAttributes: [NSAttributedString.Key: Any] = [:]
let colorA: UIColor = UIColor(red: 254.0 / 255.0, green: 76.0 / 255.0, blue: 144.0 / 255.0, alpha: 1.0)
let colorB: UIColor = UIColor(red: 201.0 / 255.0, green: 60.0 / 255.0, blue: 114.0 / 255.0, alpha: 1.0)
let colorC: UIColor = UIColor(red: 196.0 / 255.0, green: 31.0 / 255.0, blue: 58.0 / 255.0, alpha: 1.0)
let colorD: UIColor = UIColor(red: 255.0 / 255.0, green: 255.0 / 255.0, blue: 255.0 / 255.0, alpha: 1.0)
let fColorA: UIColor = UIColor(red: 53.0 / 255.0, green: 15.0 / 255.0, blue: 30.0 / 255.0, alpha: 1.0)
let fColorD: UIColor = UIColor(red: 197.0 / 255.0, green: 36.0 / 255.0, blue: 61.0 / 255.0, alpha: 1.0)
var padButtons: [CalcButton] = [CalcButton]()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor(red: 54.0 / 255.0, green: 15.0 / 255.0, blue: 30.0 / 255.0, alpha: 1.0)
padButtons = [
CalcButton(normalTitle: "←", selectedTitle: "", foreColor: fColorA, backColor: colorA),
CalcButton(normalTitle: "→", selectedTitle: "", foreColor: fColorA, backColor: colorA),
CalcButton(normalTitle: "(", selectedTitle: "", foreColor: fColorA, backColor: colorA),
CalcButton(normalTitle: "()", selectedTitle: "", foreColor: fColorA, backColor: colorA),
CalcButton(normalTitle: ")", selectedTitle: "", foreColor: fColorA, backColor: colorA),
CalcButton(normalTitle: "7", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "8", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "9", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "÷", selectedTitle: "", foreColor: .white, backColor: colorC),
CalcButton(normalTitle: "AC", selectedTitle: "", foreColor: fColorD, backColor: colorD),
CalcButton(normalTitle: "4", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "5", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "6", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "x", selectedTitle: "", foreColor: .white, backColor: colorC),
CalcButton(normalTitle: "⌫", selectedTitle: "⌦", foreColor: fColorD, backColor: colorD),
CalcButton(normalTitle: "1", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "2", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "3", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "-", selectedTitle: "", foreColor: .white, backColor: colorC),
CalcButton(normalTitle: "↖︎↘︎", selectedTitle: "", foreColor: fColorD, backColor: colorD),
CalcButton(normalTitle: "0", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: ".", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "π", selectedTitle: "", foreColor: .white, backColor: colorB),
CalcButton(normalTitle: "+", selectedTitle: "", foreColor: .white, backColor: colorC),
CalcButton(normalTitle: "✓", selectedTitle: "", foreColor: fColorD, backColor: colorD),
]
let svRows = UIStackView()
svRows.axis = .vertical
svRows.alignment = .fill
svRows.distribution = .fillEqually
svRows.spacing = 8
svRows.translatesAutoresizingMaskIntoConstraints = false
let font = UIFont.systemFont(ofSize: 28.0)
var idx = 0
for _ in 1...5 {
let svRow = UIStackView()
svRow.axis = .horizontal
svRow.alignment = .fill
svRow.distribution = .fillEqually
svRow.spacing = 8
svRow.translatesAutoresizingMaskIntoConstraints = false
for _ in 1...5 {
let cb: CalcButton = padButtons[idx]
let btn = RoundButton()
btn.backgroundColor = cb.backColor
normAttributes = [
.foregroundColor : cb.foreColor,
.underlineStyle: 0,
.font : font,
]
highAttributes = [
.foregroundColor : UIColor.lightGray,
.underlineStyle: 0,
.font : font,
]
let attNorm = NSAttributedString(string: cb.normalTitle, attributes: normAttributes)
let attHigh = NSAttributedString(string: cb.normalTitle, attributes: highAttributes)
btn.setAttributedTitle(attNorm, for: .normal)
btn.setAttributedTitle(attHigh, for: .highlighted)
if cb.selectedTitle != "" {
let attSel = NSAttributedString(string: cb.selectedTitle, attributes: normAttributes)
btn.setAttributedTitle(attSel, for: .selected)
}
btn.heightAnchor.constraint(equalTo: btn.widthAnchor).isActive = true
btn.addTarget(self, action: #selector(btnTapped(_:)), for: .touchUpInside)
svRow.addArrangedSubview(btn)
idx += 1
}
svRows.addArrangedSubview(svRow)
}
view.addSubview(inputLabel)
view.addSubview(svRows)
let g = view.safeAreaLayoutGuide
let cLeading = svRows.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 8.0)
cLeading.priority = .defaultHigh
NSLayoutConstraint.activate([
inputLabel.topAnchor.constraint(greaterThanOrEqualTo: g.topAnchor, constant: 16.0),
inputLabel.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 16.0),
inputLabel.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -8.0),
cLeading,
svRows.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -8.0),
svRows.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -8.0),
svRows.topAnchor.constraint(equalTo: inputLabel.bottomAnchor, constant: 16.0),
])
// just so we can see the frame of the inputLabel
inputLabel.backgroundColor = .gray
}
@objc func btnTapped(_ sender: Any?) -> Void {
guard let btn = sender as? UIButton, let t = btn.currentAttributedTitle?.string, let curText = inputLabel.text else {
return
}
if t == "⌫" || t == "⌦" {
btn.isSelected = !btn.isSelected
} else {
inputLabel.text = curText + t
}
}
}
结果:
关于ios - 是否可以通过编程方式将 "Button Shapes"覆盖为 Off？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60563105/