在启用自动缩小到最小字体大小的情况下检测 UILabel 的点击
Detect tap for UILabel with Autoshrink to minimum font size enabled
我正在使用我修改过的以下 UITapGestureRecognizer，以便其他人可以复制和粘贴以查看与我相同的输出。
extension UITapGestureRecognizer {
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
//let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
//mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
let textStorage = NSTextStorage(attributedString: label.attributedText!)
//let textStorage = NSTextStorage(attributedString: mutableAttribString)
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
let labelSize = label.bounds.size
print("LabelSize=",labelSize)
textContainer.size = labelSize
print("TextContainerSize=",textContainer.size)
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
print("LocationOfTouchInLabel=",locationOfTouchInLabel)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
print("TextBoundingBox=",textBoundingBox)
//let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
//(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
print("textContainerOffset",textContainerOffset)
//let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
// locationOfTouchInLabel.y - textContainerOffset.y);
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
print("LocationOfTouchInTextContainer",locationOfTouchInTextContainer)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
print("IndexOfCharacter=",indexOfCharacter)
print("TargetRange=",targetRange)
return NSLocationInRange(indexOfCharacter, targetRange)
}
}
我像这样设置标签来检测点击，就像其他答案所说的那样：
formulaLabel.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))
设置为属性。
以防万一，我有以下代码可以使用文本执行动画。
func doFormulaAnimation(){
//animTimer = Timer.scheduledTimer(withTimeInterval: 0.3, repeats: true, block: {_ in
//Draw correct formula based on mode.
var formula = ""
var highlight_ranges:[NSRange] = []
if(stateController?.tdfvariables.ebrtMode == true){
formulaLabel.numberOfLines = 1
formula = "BED = N * d * [ RBE + ( d / (α/β) ) ]"
self.formulaLabel.attributedText = NSMutableAttributedString(string: formula, attributes: [ NSAttributedString.Key.foregroundColor: UIColor.label ])
if(self.dosePerFractionSelected==true){
highlight_ranges.append(NSRange(location: 10, length: 1))
highlight_ranges.append(NSRange(location: 24, length: 1))
}
if(self.alphaBetaSelected==true){
highlight_ranges.append(NSRange(location: 29, length: 3))
}
if(self.totalDoseSelected==true){
highlight_ranges.append(NSRange(location: 6, length: 5))
}
if(self.numFractionsSelected==true){
highlight_ranges.append(NSRange(location: 6, length: 1))
}
}
if(stateController?.tdfvariables.ldrMode == true){
formulaLabel.numberOfLines = 3
formula = "BED = R * T * [RBE + (( g * R * T) / (α/β) ) ]\ng = ( 2 / μT ) * ( 1 - ( ( 1 - exp(-μT) / μT ) )\nμ = 0.693 / Thalf repair"
}
if(stateController?.tdfvariables.permMode == true){
formulaLabel.numberOfLines = 2
formula = "BED = ( R0 / L ) * [ RBE + ( R0 / ( ( u + L) * (α/β) ) ) ]\n"
}
UIView.transition(with: self.formulaLabel, duration: 0.5, options: .transitionCrossDissolve, animations: {
let colorAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.label ]
let attributedTextFormula = NSMutableAttributedString(string: formula, attributes: colorAttribute)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
attributedTextFormula.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedTextFormula.length
))
self.formulaLabel.attributedText = attributedTextFormula
//
}, completion: { finished in
print("finished first transition")
UIView.transition(with: self.formulaLabel, duration: 0.5, options: .transitionCrossDissolve, animations: {
let colorAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.label ]
let attributedTextFormula = NSMutableAttributedString(string: formula, attributes: colorAttribute)
for range in highlight_ranges {
attributedTextFormula.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.red, range: range)
}
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
attributedTextFormula.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedTextFormula.length
))
self.formulaLabel.attributedText = attributedTextFormula
//self.formulaLabel.addInterlineSpacing(spacingValue: 1)
}, completion: { finished in
print("finished second transition")
})
})
}
上面的代码演示了我相应地创建了 NSMutableString 并相应地设置了段落样式和行距（我有预感这可能是问题所在但不确定如何测试）等...
终于有了我的点击标签功能
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
guard let text = formulaLabel.attributedText?.string else {
return
}
let AB_Range = text.range(of: "(α/β)")
//let AB_Range = NSRange(location: 29, length: 3)
if gesture.didTapAttributedTextInLabel(label: formulaLabel, inRange: NSRange(AB_Range!, in: text)) {
print("Tapped a/b")
} else {
print("Tapped none")
}
}
目前没有点击正确的位置，但偏差很大。调试后很明显为什么它不起作用，但我不确定如何修复代码或哪里出错了。
当我像我应该的那样点击 A/B 时，我得到了它作为调试信息。
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (266.0, 28.0)
TextBoundingBox= (0.0, 0.0, 185.373046875, 13.8)
textContainerOffset (64.8134765625, 14.6)
LocationOfTouchInTextContainer (201.1865234375, 13.4)
IndexOfCharacter= 36
TargetRange= {28, 5}
Tapped none
它计算 textbounding box 或 textcontaineroffset 或 locationoftouchintextcontainer 的部分很可能是错误点，但我不确定是哪一个，因为这很难理解。
我可以看出它没有正常工作，因为在我的字符串中它不在接近尾声的地方，而且无论我点击它的哪个位置它总是显示 indexofcharacter=36，这意味着它没有用我的变量之一正确计算某些东西如上所述。
如果他们知道为什么这不起作用，我们将不胜感激。
为了让您了解文字现在的样子，我将在下面向您展示。我的最终目标是做到这一点，这样我就可以点击公式中的部分来显示值，所以你可以说可点击的链接。
更新::
我忘记提到当我更新 UITapGestureRecognizer 并添加这些行时：
let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
并将其设置为文本存储，let textStorage = NSTextStorage(attributedString: mutableAttribString)我确实看到数字有所改善，但仍有很大差距。
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (269.0, 25.5)
TextBoundingBox= (7.505859375, 0.0, 299.98828125, 42.9609375)
textContainerOffset (0.0, 0.01953125)
LocationOfTouchInTextContainer (269.0, 25.48046875)
IndexOfCharacter= 17
TargetRange= {28, 5}
Tapped none
您会注意到 textboundingbox 至少与 labelsize 更相似。我在某处读到如果您使用不同的字体可能会出现问题，所以这就是为什么我尝试添加它以确保它正常工作的原因。
同样有趣的是，将其添加到 UITapGestureRecognizer 似乎也有帮助：
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
mutableAttribString.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: mutableAttribString.length
))
我注意到当我执行此操作时文本边界框正确显示 0,0 而不是 7.50
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (262.5, 31.0)
TextBoundingBox= (0.0, 0.0, 299.98828125, 42.9609375)
textContainerOffset (7.505859375, 0.01953125)
LocationOfTouchInTextContainer (254.994140625, 30.98046875)
IndexOfCharacter= 17
TargetRange= {28, 5}
Tapped none
**主要更新*****
好消息！事实证明 字体修复 是修复的一部分，但是因为我启用了 自动收缩并设置了最小字体大小 和最大字体大小永远不会正确计算！ 当我设置为固定字体大小时一切正常！
现在的问题是如何让它在启用自动收缩的情况下工作？请注意，您必须将大小设置为非常大的值才能证明它有效，就像我将我的设置为 55所以它会相应地自动收缩，然后你会看到错误，如果默认大小较小，那么它似乎工作正常，这告诉我这个错误可能与最初非常大的大小有关？
所以我终于想出了一个可以接受的答案。
关键是下面的代码：
let formulaLabelWidth = formulaLabel.bounds.size.width
var font_size:CGFloat = 36.0 //Change this to a higher number if you need to.
var stringSize = NSString(string: formula).size(withAttributes: [.font : self.formulaLabel.font.withSize(font_size)])
while(stringSize.width>formulaLabelWidth){
font_size = font_size - 1
stringSize = NSString(string: formula).size(withAttributes: [.font : self.formulaLabel.font.withSize(font_size)])
}
formulaLabel.font = formulaLabel.font.withSize(font_size)
此代码所做的是绘制字符串，就好像它具有特定的字体大小，为您提供宽度和高度的边界。在我的例子中，我只关心宽度，这要归功于你在界面构建器中设置 UILabel 的技巧。
要使此策略起作用，必须在您的 UILabel 上设置它，因为它会完成所有寻找适合文本的完美尺寸的艰苦工作。
这个 确实适用于多行 以及我将它用于我的许多公式。这些行用 \n 字符分隔并自动计算在内，因为它只是增加了使用 .size(withAttributes) 函数绘制的高度。
他们曾经有一个 sizeForFont 但它被弃用了所以我研究了那个函数作为一个可能的解决方案并且确实它确实可以用一些聪明的想法。
至于检测点击，请使用我创建的以下修改后的 UITapGestureRecognizer。
extension UITapGestureRecognizer {
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.alignment = .center
mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))
let textStorage = NSTextStorage(attributedString: mutableAttribString)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
let labelSize = label.bounds.size
textContainer.size = labelSize
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
//let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
//(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
//let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
// locationOfTouchInLabel.y - textContainerOffset.y);
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
print("IndexOfCharacter=",indexOfCharacter)
print("TargetRange=",targetRange)
return NSLocationInRange(indexOfCharacter, targetRange)
}
}
请随意删除评论，但我将它们留在那里，以便您可以看到它正在选择正确的字符串索引。
另请注意，我在那里设置了一个段落设置，行间距为 6，居中对齐，因此请根据您的用例随意更改这些设置，但不要更改换行模式！这对于系统在绘制时自动找到最佳字体大小至关重要。
此代码中还引用了当前标签字体，这是我添加的新部分，因为如果没有它，文本存储计算将偏离堆栈溢出的其他答案中所指出的那样。
将其与点击手势的功能放在一起
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
guard let text = formulaLabel.attributedText?.string else {
return
}
let AB_Range = text.range(of: "(α/β)")
//let AB_Range = NSRange(location: 29, length: 3)
if gesture.didTapAttributedTextInLabel(label: formulaLabel, inRange: NSRange(AB_Range!, in: text)) {
print("Tapped a/b")
} else {
print("Tapped none")
}
}
当然，在 viewDidLoad 中或在适当的地方将点击手势设置为 UILabel...
formulaLabel.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))
而且你有自己的工作
- 多线友好
- 自动收缩友好
- 可点击友好
UILabel!
我正在使用我修改过的以下 UITapGestureRecognizer，以便其他人可以复制和粘贴以查看与我相同的输出。
extension UITapGestureRecognizer {
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
//let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
//mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
let textStorage = NSTextStorage(attributedString: label.attributedText!)
//let textStorage = NSTextStorage(attributedString: mutableAttribString)
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
let labelSize = label.bounds.size
print("LabelSize=",labelSize)
textContainer.size = labelSize
print("TextContainerSize=",textContainer.size)
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
print("LocationOfTouchInLabel=",locationOfTouchInLabel)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
print("TextBoundingBox=",textBoundingBox)
//let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
//(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
print("textContainerOffset",textContainerOffset)
//let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
// locationOfTouchInLabel.y - textContainerOffset.y);
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
print("LocationOfTouchInTextContainer",locationOfTouchInTextContainer)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
print("IndexOfCharacter=",indexOfCharacter)
print("TargetRange=",targetRange)
return NSLocationInRange(indexOfCharacter, targetRange)
}
}
我像这样设置标签来检测点击，就像其他答案所说的那样：
formulaLabel.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))
设置为属性。
以防万一，我有以下代码可以使用文本执行动画。
func doFormulaAnimation(){
//animTimer = Timer.scheduledTimer(withTimeInterval: 0.3, repeats: true, block: {_ in
//Draw correct formula based on mode.
var formula = ""
var highlight_ranges:[NSRange] = []
if(stateController?.tdfvariables.ebrtMode == true){
formulaLabel.numberOfLines = 1
formula = "BED = N * d * [ RBE + ( d / (α/β) ) ]"
self.formulaLabel.attributedText = NSMutableAttributedString(string: formula, attributes: [ NSAttributedString.Key.foregroundColor: UIColor.label ])
if(self.dosePerFractionSelected==true){
highlight_ranges.append(NSRange(location: 10, length: 1))
highlight_ranges.append(NSRange(location: 24, length: 1))
}
if(self.alphaBetaSelected==true){
highlight_ranges.append(NSRange(location: 29, length: 3))
}
if(self.totalDoseSelected==true){
highlight_ranges.append(NSRange(location: 6, length: 5))
}
if(self.numFractionsSelected==true){
highlight_ranges.append(NSRange(location: 6, length: 1))
}
}
if(stateController?.tdfvariables.ldrMode == true){
formulaLabel.numberOfLines = 3
formula = "BED = R * T * [RBE + (( g * R * T) / (α/β) ) ]\ng = ( 2 / μT ) * ( 1 - ( ( 1 - exp(-μT) / μT ) )\nμ = 0.693 / Thalf repair"
}
if(stateController?.tdfvariables.permMode == true){
formulaLabel.numberOfLines = 2
formula = "BED = ( R0 / L ) * [ RBE + ( R0 / ( ( u + L) * (α/β) ) ) ]\n"
}
UIView.transition(with: self.formulaLabel, duration: 0.5, options: .transitionCrossDissolve, animations: {
let colorAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.label ]
let attributedTextFormula = NSMutableAttributedString(string: formula, attributes: colorAttribute)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
attributedTextFormula.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedTextFormula.length
))
self.formulaLabel.attributedText = attributedTextFormula
//
}, completion: { finished in
print("finished first transition")
UIView.transition(with: self.formulaLabel, duration: 0.5, options: .transitionCrossDissolve, animations: {
let colorAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.label ]
let attributedTextFormula = NSMutableAttributedString(string: formula, attributes: colorAttribute)
for range in highlight_ranges {
attributedTextFormula.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.red, range: range)
}
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
attributedTextFormula.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedTextFormula.length
))
self.formulaLabel.attributedText = attributedTextFormula
//self.formulaLabel.addInterlineSpacing(spacingValue: 1)
}, completion: { finished in
print("finished second transition")
})
})
}
上面的代码演示了我相应地创建了 NSMutableString 并相应地设置了段落样式和行距（我有预感这可能是问题所在但不确定如何测试）等...
终于有了我的点击标签功能
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
guard let text = formulaLabel.attributedText?.string else {
return
}
let AB_Range = text.range(of: "(α/β)")
//let AB_Range = NSRange(location: 29, length: 3)
if gesture.didTapAttributedTextInLabel(label: formulaLabel, inRange: NSRange(AB_Range!, in: text)) {
print("Tapped a/b")
} else {
print("Tapped none")
}
}
目前没有点击正确的位置，但偏差很大。调试后很明显为什么它不起作用，但我不确定如何修复代码或哪里出错了。
当我像我应该的那样点击 A/B 时，我得到了它作为调试信息。
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (266.0, 28.0)
TextBoundingBox= (0.0, 0.0, 185.373046875, 13.8)
textContainerOffset (64.8134765625, 14.6)
LocationOfTouchInTextContainer (201.1865234375, 13.4)
IndexOfCharacter= 36
TargetRange= {28, 5}
Tapped none
它计算 textbounding box 或 textcontaineroffset 或 locationoftouchintextcontainer 的部分很可能是错误点，但我不确定是哪一个，因为这很难理解。
我可以看出它没有正常工作，因为在我的字符串中它不在接近尾声的地方，而且无论我点击它的哪个位置它总是显示 indexofcharacter=36，这意味着它没有用我的变量之一正确计算某些东西如上所述。
如果他们知道为什么这不起作用，我们将不胜感激。
为了让您了解文字现在的样子，我将在下面向您展示。我的最终目标是做到这一点，这样我就可以点击公式中的部分来显示值，所以你可以说可点击的链接。
更新::
我忘记提到当我更新 UITapGestureRecognizer 并添加这些行时：
let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
并将其设置为文本存储，let textStorage = NSTextStorage(attributedString: mutableAttribString)我确实看到数字有所改善，但仍有很大差距。
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (269.0, 25.5)
TextBoundingBox= (7.505859375, 0.0, 299.98828125, 42.9609375)
textContainerOffset (0.0, 0.01953125)
LocationOfTouchInTextContainer (269.0, 25.48046875)
IndexOfCharacter= 17
TargetRange= {28, 5}
Tapped none
您会注意到 textboundingbox 至少与 labelsize 更相似。我在某处读到如果您使用不同的字体可能会出现问题，所以这就是为什么我尝试添加它以确保它正常工作的原因。
同样有趣的是，将其添加到 UITapGestureRecognizer 似乎也有帮助：
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
//paragraphStyle.alignment = .center
mutableAttribString.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: mutableAttribString.length
))
我注意到当我执行此操作时文本边界框正确显示 0,0 而不是 7.50
LabelSize= (315.0, 43.0)
TextContainerSize= (315.0, 43.0)
LocationOfTouchInLabel= (262.5, 31.0)
TextBoundingBox= (0.0, 0.0, 299.98828125, 42.9609375)
textContainerOffset (7.505859375, 0.01953125)
LocationOfTouchInTextContainer (254.994140625, 30.98046875)
IndexOfCharacter= 17
TargetRange= {28, 5}
Tapped none
**主要更新*****
好消息！事实证明 字体修复 是修复的一部分，但是因为我启用了 自动收缩并设置了最小字体大小 和最大字体大小永远不会正确计算！ 当我设置为固定字体大小时一切正常！
现在的问题是如何让它在启用自动收缩的情况下工作？请注意，您必须将大小设置为非常大的值才能证明它有效，就像我将我的设置为 55所以它会相应地自动收缩，然后你会看到错误，如果默认大小较小，那么它似乎工作正常，这告诉我这个错误可能与最初非常大的大小有关？
所以我终于想出了一个可以接受的答案。
关键是下面的代码：
let formulaLabelWidth = formulaLabel.bounds.size.width
var font_size:CGFloat = 36.0 //Change this to a higher number if you need to.
var stringSize = NSString(string: formula).size(withAttributes: [.font : self.formulaLabel.font.withSize(font_size)])
while(stringSize.width>formulaLabelWidth){
font_size = font_size - 1
stringSize = NSString(string: formula).size(withAttributes: [.font : self.formulaLabel.font.withSize(font_size)])
}
formulaLabel.font = formulaLabel.font.withSize(font_size)
此代码所做的是绘制字符串，就好像它具有特定的字体大小，为您提供宽度和高度的边界。在我的例子中，我只关心宽度，这要归功于你在界面构建器中设置 UILabel 的技巧。
要使此策略起作用，必须在您的 UILabel 上设置它，因为它会完成所有寻找适合文本的完美尺寸的艰苦工作。
这个 确实适用于多行 以及我将它用于我的许多公式。这些行用 \n 字符分隔并自动计算在内，因为它只是增加了使用 .size(withAttributes) 函数绘制的高度。
他们曾经有一个 sizeForFont 但它被弃用了所以我研究了那个函数作为一个可能的解决方案并且确实它确实可以用一些聪明的想法。
至于检测点击，请使用我创建的以下修改后的 UITapGestureRecognizer。
extension UITapGestureRecognizer {
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.alignment = .center
mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))
let textStorage = NSTextStorage(attributedString: mutableAttribString)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
let labelSize = label.bounds.size
textContainer.size = labelSize
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
//let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
//(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
//let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
// locationOfTouchInLabel.y - textContainerOffset.y);
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
print("IndexOfCharacter=",indexOfCharacter)
print("TargetRange=",targetRange)
return NSLocationInRange(indexOfCharacter, targetRange)
}
}
请随意删除评论，但我将它们留在那里，以便您可以看到它正在选择正确的字符串索引。
另请注意，我在那里设置了一个段落设置，行间距为 6，居中对齐，因此请根据您的用例随意更改这些设置，但不要更改换行模式！这对于系统在绘制时自动找到最佳字体大小至关重要。
此代码中还引用了当前标签字体，这是我添加的新部分，因为如果没有它，文本存储计算将偏离堆栈溢出的其他答案中所指出的那样。
将其与点击手势的功能放在一起
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
guard let text = formulaLabel.attributedText?.string else {
return
}
let AB_Range = text.range(of: "(α/β)")
//let AB_Range = NSRange(location: 29, length: 3)
if gesture.didTapAttributedTextInLabel(label: formulaLabel, inRange: NSRange(AB_Range!, in: text)) {
print("Tapped a/b")
} else {
print("Tapped none")
}
}
当然，在 viewDidLoad 中或在适当的地方将点击手势设置为 UILabel...
formulaLabel.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))
而且你有自己的工作
- 多线友好
- 自动收缩友好
- 可点击友好
UILabel!