前言:AttributedString是Apple推出的可以实现单个字符或字符范围带相应属性的字符串。属性提供了一些文本特性,可以让文本展示的样式更加丰富。在日常开发过程中,我通常用于同一个Label中包含不同的字体大小或字体颜色的样式编写中。
使用举例
需求:需要设置一个红底白字的Label
swift
attributedLabel = UILabel()
let contentStr = NSString(string: "AttributedString")
let attStr = NSMutableAttributedString(string: contentStr as String)
attStr.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 20, weight: .medium), range: NSRange(location: 0, length: contentStr.length))
attStr.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.white, range: NSRange(location: 0, length: contentStr.length))
attStr.addAttribute(NSAttributedString.Key.backgroundColor, value: UIColor.red, range: NSRange(location: 0, length: contentStr.length))
attributedLabel.attributedText = attStr
样式展示:
文本属性介绍
从上方代码可以看出,文本的属性是通过设置文本字体,文本颜色,文本背景颜色所实现的。所以下面来一一列举一些常用的文本属性及展示效果。
- 设置文本字体大小和粗细
swift
attStr.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 20, weight: .medium), range: NSRange(location: 0, length: contentStr.length))
效果:
- 设置文本颜色
swift
attStr.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.blue, range: NSRange(location: 0, length: contentStr.length))
效果:
- 设置背景颜色
swift
attStr.addAttribute(NSAttributedString.Key.backgroundColor, value: UIColor.red, range: NSRange(location: 0, length: contentStr.length))
效果:
- 设置下划线
swift
attStr.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSRange(location: 0, length: contentStr.length))
效果:
- 设置下划线颜色
默认下划线颜色与文本颜色相同
swift
attStr.addAttribute(NSAttributedString.Key.underlineColor, value: UIColor.green, range: NSRange(location: 0, length: contentStr.length))
效果:
- 拼接文本
先设置好相关文本属性,然后将其相互连接
swift
let contentStr1 = NSString(string: "Attributed")
let attStr1 = NSMutableAttributedString(string: contentStr1 as String)
attStr1.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 20, weight: .medium), range: NSRange(location: 0, length: contentStr1.length))
attStr1.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.blue, range: NSRange(location: 0, length: contentStr1.length))
let contentStr2 = NSString(string: "String")
let attStr2 = NSMutableAttributedString(string: contentStr2 as String)
attStr2.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 12, weight: .medium), range: NSRange(location: 0, length: contentStr2.length))
attStr2.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.green, range: NSRange(location: 0, length: contentStr2.length))
attStr1.append(attStr2)
attributedLabel.attributedText = attStr1
效果:
Attributes创建及使用
attributes可以一次性创建多个属性,attributes是一个字典
需求:创建一个红底白字的Label
swift
let contentStr = NSString(string: "AttributedString")
let attStr = NSMutableAttributedString(string: contentStr as String)
attStr.addAttributes([NSAttributedString.Key.font: UIFont.systemFont(ofSize: 20, weight: .regular),
NSAttributedString.Key.foregroundColor : UIColor.white,
NSAttributedString.Key.backgroundColor : UIColor.red], range: NSRange(location: 0, length: contentStr.length))
attributedLabel.attributedText = attStr
效果:
常用属性方法整合
我将常用的一些文本属性进行整合了一个类
swift
import Foundation
import UIKit
public struct ZUAttributedString {
public enum Font:String {
case thin = "PingFangSC-Thin"
case light = "PingFangSC-Light"
case medium = "PingFangSC-Medium"
case regular = "PingFangSC-Regular"
}
public enum Line{
case none
case midLine
case underLine
}
public static func attributeString(content:String,
font: UIFont,
alignment:NSTextAlignment? = NSTextAlignment.center,
textColor:UIColor?,
backgroundColor: UIColor? = nil,
line:Line = .none,
lineSpacing:CGFloat = 0) -> NSMutableAttributedString
{
let contentStr = NSString(string: content)
let attStr = NSMutableAttributedString(string: contentStr as String)
//set color
if let textColor = textColor {
attStr.addAttribute(NSAttributedString.Key.foregroundColor, value: textColor, range: NSRange(location: 0, length: contentStr.length))
}
if let backgroundColor = backgroundColor {
attStr.addAttribute(NSAttributedString.Key.backgroundColor, value: backgroundColor, range: NSRange(location: 0, length: contentStr.length))
}
let style = NSMutableParagraphStyle()
if let align = alignment {
style.alignment = align
} else {
style.alignment = NSTextAlignment.center
}
if lineSpacing > 0{
style.lineSpacing = lineSpacing
}
attStr.addAttribute(NSAttributedString.Key.paragraphStyle, value: style, range: NSRange(location: 0, length: contentStr.length))
attStr.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: contentStr.length))
switch line{
case .none:
break
case .midLine:
attStr.addAttribute(NSAttributedString.Key.strikethroughStyle, value: NSUnderlineStyle.single.rawValue, range: NSMakeRange(0, attStr.length))
break
case .underLine:
attStr.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSMakeRange(0, attStr.length))
break
}
return attStr
}
public static func attributeString(content:String,
font:ZUAttributedString.Font,
size:CGFloat,
alignment:NSTextAlignment? = NSTextAlignment.center,
textColor:UIColor?,
backgroundColor:UIColor? = nil,
line:Line = .none,
maximumLineHeight:CGFloat) -> NSMutableAttributedString
{
let attStr = NSMutableAttributedString(string: content)
//set color
if let textColor = textColor {
attStr.addAttribute(NSAttributedString.Key.foregroundColor, value: textColor, range: NSRange(location: 0, length: content.count))
}
if let backgroundColor = backgroundColor {
attStr.addAttribute(NSAttributedString.Key.backgroundColor, value: backgroundColor, range: NSRange(location: 0, length: content.count))
}
let style = NSMutableParagraphStyle()
if let align = alignment {
style.alignment = align
} else {
style.alignment = NSTextAlignment.center
}
attStr.addAttribute(NSAttributedString.Key.paragraphStyle, value: style, range: NSRange(location: 0, length: content.count))
//set font
switch font {
case .thin:
let font = UIFont(name: ZUAttributedString.Font.thin.rawValue, size: size) ?? UIFont.systemFont(ofSize: size)
attStr.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: content.count))
case .light:
let font = UIFont(name: ZUAttributedString.Font.light.rawValue, size: size) ?? UIFont.systemFont(ofSize: size)
attStr.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: content.count))
break
case .medium:
let font = UIFont(name: ZUAttributedString.Font.medium.rawValue, size: size) ?? UIFont.systemFont(ofSize: size)
attStr.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: content.count))
break
case .regular:
let font = UIFont(name: ZUAttributedString.Font.regular.rawValue, size: size) ?? UIFont.systemFont(ofSize: size)
attStr.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: content.count))
break
}
switch line{
case .none:
break
case .midLine:
attStr.addAttribute(NSAttributedString.Key.strikethroughStyle, value: NSUnderlineStyle.single.rawValue, range: NSMakeRange(0, attStr.length))
break
case .underLine:
attStr.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSMakeRange(0, attStr.length))
break
}
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.maximumLineHeight = maximumLineHeight
// Line spacing attribute
attStr.addAttribute(NSAttributedString.Key.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attStr.length))
return attStr
}
}
方法使用:
swift
let attStr1 = ZUAttributedString.attributeString(content: "Attributed", font: UIFont.systemFont(ofSize: 20, weight: .regular), textColor: UIColor.green, backgroundColor: nil)
let attStr2 = ZUAttributedString.attributeString(content: "String", font: UIFont.systemFont(ofSize: 20, weight: .regular), textColor: UIColor.blue, backgroundColor: nil)
attStr1.append(attStr2)
效果:
所以通过方法整合的方式,可以更加方便便捷的使用AttributedString,并且也可以更好的实现我们目标的文本样式
参考文章
iOS swift 带有attributeString的多行文本label
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