我想制作一个简单的咖啡计算器。我需要以克为单位显示咖啡量。克的“g”符号需要附加到我用来显示金额的UILabel上。 UILabel中的数字正在根据用户输入动态变化,但我需要在字符串末尾添加小写“g”,其格式与更新数字不同。需要将“g”附加到数字上,以便随着数字大小和位置的变化,“g”随着数字“移动”。我确定这个问题已经解决了,所以正确的方向链接会有所帮助,因为我已经搜索了我的小心脏。
我在文档中搜索了一个属性字符串,我甚至从应用程序商店下载了一个“Attributed String Creator”,但结果代码是在Objective-C中,我使用的是Swift。什么是令人敬畏的,并且可能对其他开发人员学习这种语言有帮助,这是使用Swift中的属性字符串创建具有自定义属性的自定义字体的明显示例。这方面的文档非常令人困惑,因为没有非常明确的方法来解决这个问题。我的计划是创建属性字符串并将其添加到coffeeAmount字符串的末尾。
var coffeeAmount: String = calculatedCoffee + attributedText
其中calculateCoffee是一个Int转换为字符串,“attributedText”是小写的“g”,带有我想要创建的自定义字体。也许我会以错误的方式解决这个问题。任何帮助表示赞赏!
此答案已针对Swift 4.2进行了更新。
制作和设置属性字符串的一般形式是这样的。您可以在下面找到其他常见选项。
// create attributed string
let myString = "Swift Attributed String"
let myAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.blue ]
let myAttrString = NSAttributedString(string: myString, attributes: myAttribute)
// set attributed text on a UILabel
myLabel.attributedText = myAttrString
let myAttribute = [ NSAttributedString.Key.foregroundColor: UIColor.blue ]
let myAttribute = [ NSAttributedString.Key.backgroundColor: UIColor.yellow ]
let myAttribute = [ NSAttributedString.Key.font: UIFont(name: "Chalkduster", size: 18.0)! ]
let myAttribute = [ NSAttributedString.Key.underlineStyle: NSUnderlineStyle.single.rawValue ]
let myShadow = NSShadow()
myShadow.shadowBlurRadius = 3
myShadow.shadowOffset = CGSize(width: 3, height: 3)
myShadow.shadowColor = UIColor.gray
let myAttribute = [ NSAttributedString.Key.shadow: myShadow ]
这篇文章的其余部分为感兴趣的人提供了更多细节。
字符串属性只是[NSAttributedString.Key: Any]
形式的字典,其中NSAttributedString.Key
是属性的关键名称,Any
是某些Type的值。值可以是字体,颜色,整数或其他内容。 Swift中有许多已经预定义的标准属性。例如:
NSAttributedString.Key.font
,价值:a UIFont
NSAttributedString.Key.foregroundColor
,价值:a UIColor
NSAttributedString.Key.link
,价值:NSURL
或NSString
还有很多其他的。有关更多信息,请参阅this link。您甚至可以制作自己的自定义属性,例如:
NSAttributedString.Key.myName
,值:某些类型。
如果你做一个extension:
extension NSAttributedString.Key {
static let myName = NSAttributedString.Key(rawValue: "myCustomAttributeKey")
}
您可以声明属性,就像声明任何其他字典一样。
// single attributes declared one at a time
let singleAttribute1 = [ NSAttributedString.Key.foregroundColor: UIColor.green ]
let singleAttribute2 = [ NSAttributedString.Key.backgroundColor: UIColor.yellow ]
let singleAttribute3 = [ NSAttributedString.Key.underlineStyle: NSUnderlineStyle.double.rawValue ]
// multiple attributes declared at once
let multipleAttributes: [NSAttributedString.Key : Any] = [
NSAttributedString.Key.foregroundColor: UIColor.green,
NSAttributedString.Key.backgroundColor: UIColor.yellow,
NSAttributedString.Key.underlineStyle: NSUnderlineStyle.double.rawValue ]
// custom attribute
let customAttribute = [ NSAttributedString.Key.myName: "Some value" ]
请注意下划线样式值所需的rawValue
。
因为属性只是字典,所以您也可以通过创建一个空字典然后向其添加键值对来创建它们。如果该值包含多个类型,则必须使用Any
作为类型。以下是上面的multipleAttributes
示例,以这种方式重新创建:
var multipleAttributes = [NSAttributedString.Key : Any]()
multipleAttributes[NSAttributedString.Key.foregroundColor] = UIColor.green
multipleAttributes[NSAttributedString.Key.backgroundColor] = UIColor.yellow
multipleAttributes[NSAttributedString.Key.underlineStyle] = NSUnderlineStyle.double.rawValue
既然您了解了属性,那么您可以创建属性字符串。
初始化
有几种方法可以创建属性字符串。如果你只需要一个只读字符串,你可以使用NSAttributedString
。以下是一些初始化方法:
// Initialize with a string only
let attrString1 = NSAttributedString(string: "Hello.")
// Initialize with a string and inline attribute(s)
let attrString2 = NSAttributedString(string: "Hello.", attributes: [NSAttributedString.Key.myName: "A value"])
// Initialize with a string and separately declared attribute(s)
let myAttributes1 = [ NSAttributedString.Key.foregroundColor: UIColor.green ]
let attrString3 = NSAttributedString(string: "Hello.", attributes: myAttributes1)
如果以后需要更改属性或字符串内容,则应使用NSMutableAttributedString
。声明非常相似:
// Create a blank attributed string
let mutableAttrString1 = NSMutableAttributedString()
// Initialize with a string only
let mutableAttrString2 = NSMutableAttributedString(string: "Hello.")
// Initialize with a string and inline attribute(s)
let mutableAttrString3 = NSMutableAttributedString(string: "Hello.", attributes: [NSAttributedString.Key.myName: "A value"])
// Initialize with a string and separately declared attribute(s)
let myAttributes2 = [ NSAttributedString.Key.foregroundColor: UIColor.green ]
let mutableAttrString4 = NSMutableAttributedString(string: "Hello.", attributes: myAttributes2)
举个例子,让我们在这篇文章的顶部创建一个属性字符串。
首先使用新的字体属性创建一个NSMutableAttributedString
。
let myAttribute = [ NSAttributedString.Key.font: UIFont(name: "Chalkduster", size: 18.0)! ]
let myString = NSMutableAttributedString(string: "Swift", attributes: myAttribute )
如果您正在使用,请将属性字符串设置为UITextView
(或UILabel
),如下所示:
textView.attributedText = myString
你不使用textView.text
。
结果如下:
然后附加另一个没有设置任何属性的属性字符串。 (请注意,即使我使用let
来声明上面的myString
,我仍然可以修改它,因为它是一个NSMutableAttributedString
。这对我来说似乎相当不顺畅,如果将来发生变化我也不会感到惊讶。请给我留言发生。)
let attrString = NSAttributedString(string: " Attributed Strings")
myString.append(attrString)
接下来我们只选择“Strings”一词,它从索引17
开始,长度为7
。请注意,这是一个NSRange
而不是Swift Range
。 (有关Ranges的更多信息,请参阅this answer。)addAttribute
方法允许我们将属性键名称放在第一个点,第二个点中的属性值和第三个点中的范围。
var myRange = NSRange(location: 17, length: 7) // range starting at location 17 with a lenth of 7: "Strings"
myString.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.red, range: myRange)
最后,让我们添加背景颜色。为了变化,让我们使用addAttributes
方法(注意s
)。我可以使用此方法一次添加多个属性,但我将再次添加一个。
myRange = NSRange(location: 3, length: 17)
let anotherAttribute = [ NSAttributedString.Key.backgroundColor: UIColor.yellow ]
myString.addAttributes(anotherAttribute, range: myRange)
请注意,属性在某些地方重叠。添加属性不会覆盖已存在的属性。
我创建了一个可以解决您问题的在线工具!您可以编写字符串并以图形方式应用样式,该工具为您提供objective-c和swift代码以生成该字符串。
也是开源的,所以随意扩展它并发送PR。
对我来说,在设置特定颜色或属性时,解决方案不起作用。
这确实有效:
let attributes = [
NSFontAttributeName : UIFont(name: "Helvetica Neue", size: 12.0)!,
NSUnderlineStyleAttributeName : 1,
NSForegroundColorAttributeName : UIColor.darkGrayColor(),
NSTextEffectAttributeName : NSTextEffectLetterpressStyle,
NSStrokeWidthAttributeName : 3.0]
var atriString = NSAttributedString(string: "My Attributed String", attributes: attributes)
func decorateText(sub:String, des:String)->NSAttributedString{
let textAttributesOne = [NSAttributedStringKey.foregroundColor: UIColor.darkText, NSAttributedStringKey.font: UIFont(name: "PTSans-Bold", size: 17.0)!]
let textAttributesTwo = [NSAttributedStringKey.foregroundColor: UIColor.black, NSAttributedStringKey.font: UIFont(name: "PTSans-Regular", size: 14.0)!]
let textPartOne = NSMutableAttributedString(string: sub, attributes: textAttributesOne)
let textPartTwo = NSMutableAttributedString(string: des, attributes: textAttributesTwo)
let textCombination = NSMutableAttributedString()
textCombination.append(textPartOne)
textCombination.append(textPartTwo)
return textCombination
}
//实现
cell.lblFrom.attributedText = decorateText(sub: sender!, des: " - \(convertDateFormatShort3(myDateString: datetime!))")
斯威夫特4
let attributes = [NSAttributedStringKey.font : UIFont(name: CustomFont.NAME_REGULAR.rawValue, size: CustomFontSize.SURVEY_FORM_LABEL_SIZE.rawValue)!]
let attributedString : NSAttributedString = NSAttributedString(string: messageString, attributes: attributes)
您需要删除swift 4中的原始值
Swift 2.1 - Xcode 7
let labelFont = UIFont(name: "HelveticaNeue-Bold", size: 18)
let attributes :[String:AnyObject] = [NSFontAttributeName : labelFont!]
let attrString = NSAttributedString(string:"foo", attributes: attributes)
myLabel.attributedText = attrString
extension UILabel{
func setSubTextColor(pSubString : String, pColor : UIColor){
let attributedString: NSMutableAttributedString = self.attributedText != nil ? NSMutableAttributedString(attributedString: self.attributedText!) : NSMutableAttributedString(string: self.text!);
let range = attributedString.mutableString.range(of: pSubString, options:NSString.CompareOptions.caseInsensitive)
if range.location != NSNotFound {
attributedString.addAttribute(NSForegroundColorAttributeName, value: pColor, range: range);
}
self.attributedText = attributedString
}
}
属性可以直接在swift 3中设置......
let attributes = NSAttributedString(string: "String", attributes: [NSFontAttributeName : UIFont(name: "AvenirNext-Medium", size: 30)!,
NSForegroundColorAttributeName : UIColor .white,
NSTextEffectAttributeName : NSTextEffectLetterpressStyle])
然后在任何具有属性的类中使用该变量
let attrString = NSAttributedString (
string: "title-title-title",
attributes: [NSAttributedStringKey.foregroundColor: UIColor.black])
用我创建的库来解决你的问题真的很容易。它被称为Atributika。
let calculatedCoffee: Int = 768
let g = Style("g").font(.boldSystemFont(ofSize: 12)).foregroundColor(.red)
let all = Style.font(.systemFont(ofSize: 12))
let str = "\(calculatedCoffee)<g>g</g>".style(tags: g)
.styleAll(all)
.attributedString
label.attributedText = str
Swift 4.2
extension UILabel {
func boldSubstring(_ substr: String) {
guard substr.isEmpty == false,
let text = attributedText,
let range = text.string.range(of: substr, options: .caseInsensitive) else {
return
}
let attr = NSMutableAttributedString(attributedString: text)
let start = text.string.distance(from: text.string.startIndex, to: range.lowerBound)
let length = text.string.distance(from: range.lowerBound, to: range.upperBound)
attr.addAttributes([NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: self.font.pointSize)],
range: NSMakeRange(start, length))
attributedText = attr
}
}
Swift使用与Obj-C相同的NSMutableAttributedString
。您通过将计算的值作为字符串传递来实例化它:
var attributedString = NSMutableAttributedString(string:"\(calculatedCoffee)")
现在创建属性g
字符串(heh)。注意:UIFont.systemFontOfSize(_)
现在是一个可用的初始化程序,因此必须先将其解包,然后才能使用它:
var attrs = [NSFontAttributeName : UIFont.systemFontOfSize(19.0)!]
var gString = NSMutableAttributedString(string:"g", attributes:attrs)
然后追加它:
attributedString.appendAttributedString(gString)
然后,您可以设置UILabel以显示NSAttributedString,如下所示:
myLabel.attributedText = attributedString
斯威夫特5及以上
let attributedString = NSAttributedString(string:"targetString",
attributes:[NSAttributedString.Key.foregroundColor: UIColor.lightGray,
NSAttributedString.Key.font: UIFont(name: "Arial", size: 18.0) as Any])
Swift 4.x
let attr = [NSForegroundColorAttributeName:self.configuration.settingsColor, NSFontAttributeName: self.configuration.settingsFont]
let title = NSAttributedString(string: self.configuration.settingsTitle,
attributes: attr)
Swift 3.0 //创建属性字符串
定义类似的属性
let attributes = [NSAttributedStringKey.font : UIFont.init(name: "Avenir-Medium", size: 13.0)]
请考虑使用Prestyler
import Prestyler
...
Prestyle.defineRule("$", UIColor.red)
label.attributedText = "\(calculatedCoffee) $g$".prestyled()
Swifter Swift有一个非常甜蜜的方式,没有任何工作真的这样做。只提供应该匹配的模式以及要应用于它的属性。他们非常适合做很多事情。
``` Swift
let defaultGenreText = NSAttributedString(string: "Select Genre - Required")
let redGenreText = defaultGenreText.applying(attributes: [NSAttributedString.Key.foregroundColor : UIColor.red], toRangesMatching: "Required")
``
如果你有多个地方可以应用这个,你只希望它发生在特定的实例上,那么这个方法是行不通的。
您可以一步完成此操作,分离时更容易阅读。
extension String {
//MARK: Getting customized string
struct StringAttribute {
var fontName = "HelveticaNeue-Bold"
var fontSize: CGFloat?
var initialIndexOftheText = 0
var lastIndexOftheText: Int?
var textColor: UIColor = .black
var backGroundColor: UIColor = .clear
var underLineStyle: NSUnderlineStyle = .styleNone
var textShadow: TextShadow = TextShadow()
var fontOfText: UIFont {
if let font = UIFont(name: fontName, size: fontSize!) {
return font
} else {
return UIFont(name: "HelveticaNeue-Bold", size: fontSize!)!
}
}
struct TextShadow {
var shadowBlurRadius = 0
var shadowOffsetSize = CGSize(width: 0, height: 0)
var shadowColor: UIColor = .clear
}
}
func getFontifiedText(partOfTheStringNeedToConvert partTexts: [StringAttribute]) -> NSAttributedString {
let fontChangedtext = NSMutableAttributedString(string: self, attributes: [NSFontAttributeName: UIFont(name: "HelveticaNeue-Bold", size: (partTexts.first?.fontSize)!)!])
for eachPartText in partTexts {
let lastIndex = eachPartText.lastIndexOftheText ?? self.count
let attrs = [NSFontAttributeName : eachPartText.fontOfText, NSForegroundColorAttributeName: eachPartText.textColor, NSBackgroundColorAttributeName: eachPartText.backGroundColor, NSUnderlineStyleAttributeName: eachPartText.underLineStyle, NSShadowAttributeName: eachPartText.textShadow ] as [String : Any]
let range = NSRange(location: eachPartText.initialIndexOftheText, length: lastIndex - eachPartText.initialIndexOftheText)
fontChangedtext.addAttributes(attrs, range: range)
}
return fontChangedtext
}
}
//如下所示使用它
let someAttributedText = "Some Text".getFontifiedText(partOfTheStringNeedToConvert: <#T##[String.StringAttribute]#>)
斯威夫特4:
let attributes = [NSAttributedStringKey.font: UIFont(name: "HelveticaNeue-Bold", size: 17)!,
NSAttributedStringKey.foregroundColor: UIColor.white]
Xcode 6版本:
let attriString = NSAttributedString(string:"attriString", attributes:
[NSForegroundColorAttributeName: UIColor.lightGrayColor(),
NSFontAttributeName: AttriFont])
Xcode 9.3版本:
let attriString = NSAttributedString(string:"attriString", attributes:
[NSAttributedStringKey.foregroundColor: UIColor.lightGray,
NSAttributedStringKey.font: AttriFont])
Xcode 10,iOS 12,Swift 4:
let attriString = NSAttributedString(string:"attriString", attributes:
[NSAttributedString.Key.foregroundColor: UIColor.lightGray,
NSAttributedString.Key.font: AttriFont])
Swift:xcode 6.1
let font:UIFont? = UIFont(name: "Arial", size: 12.0)
let attrString = NSAttributedString(
string: titleData,
attributes: NSDictionary(
object: font!,
forKey: NSFontAttributeName))
我强烈建议使用库来归因字符串。它可以让你更容易,例如,一个字符串有四种不同的颜色和四种不同的字体。 Here is my favorite.它被称为SwiftyAttributes
如果你想使用SwiftyAttributes制作一个包含四种不同颜色和不同字体的字符串:
let magenta = "Hello ".withAttributes([
.textColor(.magenta),
.font(.systemFont(ofSize: 15.0))
])
let cyan = "Sir ".withAttributes([
.textColor(.cyan),
.font(.boldSystemFont(ofSize: 15.0))
])
let green = "Lancelot".withAttributes([
.textColor(.green),
.font(.italicSystemFont(ofSize: 15.0))
])
let blue = "!".withAttributes([
.textColor(.blue),
.font(.preferredFont(forTextStyle: UIFontTextStyle.headline))
])
let finalString = magenta + cyan + green + blue
finalString
将表现为
在测试版6中运行良好
let attrString = NSAttributedString(
string: "title-title-title",
attributes: NSDictionary(
object: NSFont(name: "Arial", size: 12.0),
forKey: NSFontAttributeName))
Swift 2.0
这是一个示例:
let newsString: NSMutableAttributedString = NSMutableAttributedString(string: "Tap here to read the latest Football News.")
newsString.addAttributes([NSUnderlineStyleAttributeName: NSUnderlineStyle.StyleDouble.rawValue], range: NSMakeRange(4, 4))
sampleLabel.attributedText = newsString.copy() as? NSAttributedString
要么
let stringAttributes = [
NSFontAttributeName : UIFont(name: "Helvetica Neue", size: 17.0)!,
NSUnderlineStyleAttributeName : 1,
NSForegroundColorAttributeName : UIColor.orangeColor(),
NSTextEffectAttributeName : NSTextEffectLetterpressStyle,
NSStrokeWidthAttributeName : 2.0]
let atrributedString = NSAttributedString(string: "Sample String: Attributed", attributes: stringAttributes)
sampleLabel.attributedText = atrributedString
在iOS上使用Attributed Strings的最佳方法是在界面构建器中使用内置的Attributed Text编辑器,并避免在源文件中使用不必要的硬编码NSAtrributedStringKeys。
您可以稍后使用此扩展名在运行时动态替换placehoderls:
extension NSAttributedString {
func replacing(placeholder:String, with valueString:String) -> NSAttributedString {
if let range = self.string.range(of:placeholder) {
let nsRange = NSRange(range,in:valueString)
let mutableText = NSMutableAttributedString(attributedString: self)
mutableText.replaceCharacters(in: nsRange, with: valueString)
return mutableText as NSAttributedString
}
return self
}
}
添加一个故事板标签,其属性文本如下所示。
然后,您只需在每次需要时更新值,如下所示:
label.attributedText = initalAttributedString.replacing(placeholder: "<price>", with: newValue)
确保将原始值保存到initalAttributedString中。
您可以通过阅读本文来更好地理解这种方法:https://medium.com/mobile-appetite/text-attributes-on-ios-the-effortless-approach-ff086588173e