TextKit的相關(guān)知識可以看這一篇文章：點(diǎn)我
要使UILabel用上TextKit，需要自定義UILabel
先看看使用這個自定義Label的demo
demo.gif
1. 自定義UILabel并創(chuàng)建TextKit三個核心對象
/// NSAttributedString 子類 設(shè)置文本統(tǒng)一使用
fileprivate lazy var textStorage = NSTextStorage()
/// 布局管理器 負(fù)責(zé) 字形 布局
fileprivate lazy var layoutManager = NSLayoutManager()
/// 繪制區(qū)域
fileprivate lazy var textContainer = NSTextContainer()
2.設(shè)置TextKit
/// 準(zhǔn)備文本系統(tǒng)
fileprivate func prepareTextSystem() {
adjustsFontSizeToFitWidth = true
// 打開交互
isUserInteractionEnabled = true
// 準(zhǔn)備文本內(nèi)容
prepareText()
// 設(shè)置對象的關(guān)系
textStorage.addLayoutManager(layoutManager)
layoutManager.addTextContainer(textContainer)
}
/// 準(zhǔn)備文本內(nèi)容 - 使用TextStorage 接管 label內(nèi)容
fileprivate func prepareText() {
if let attributedText = attributedText {
textStorage.setAttributedString(attributedText)
}else if let text = text {
textStorage.setAttributedString(NSAttributedString(string: text))
}else {
textStorage.setAttributedString(NSAttributedString(string: ""))
return
}
-
上一步需要在label初始化的時候執(zhí)行，所以需要兩個構(gòu)造器里調(diào)用此方法
// 代碼創(chuàng)建
override init(frame: CGRect) {
super.init(frame: frame)
prepareTextSystem()
}
// xib創(chuàng)建
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
prepareTextSystem()
}
-
指定文本繪制區(qū)域
override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = bounds.size
}
-
繪制textStorage的文本內(nèi)容
override func drawText(in rect: CGRect) {
// 繪制背景
let range = NSRange(location: 0, length: textStorage.length)
layoutManager.drawBackground(forGlyphRange: range, at: CGPoint(x: 0, y: 0))
// 繪制字形
layoutManager.drawGlyphs(forGlyphRange: range, at: CGPoint(x: -5, y: 0))
}
注意：必須先繪制背景才能繪制字形！否則背景會覆蓋字形
到此，TextKit基本設(shè)置完了。
3. 利用正則尋找需要高亮的內(nèi)容
例如微博需要高亮
鏈接
@用戶
#話題#
根據(jù)正則表達(dá)式在textStorage中尋找對應(yīng)的range
private func findRanges(pattern: String) -> [NSRange]? {
guard let regx = try? NSRegularExpression(pattern: pattern, options: []) else {
return nil
}
let matches = regx.matches(in: textStorage.string, options: [], range: NSRange(location: 0, length: textStorage.length))
var ranges = [NSRange]()
for match in matches {
ranges.append(match.rangeAt(0))
}
return ranges
}
- 定義計算型屬性保存ranges
/// 鏈接
var urlRanges: [NSRange]? {
let pattern = "\\b(([\\w-]+://?|www[.])[^\\s()<>]+(?:\\([\\w\\d]+\\)|([^[:punct:]\\s]|/)))"
return findRanges(pattern: pattern)
}
/// 話題
var topicRanges: [NSRange]? {
let pattern = "#[^#]+#"
return findRanges(pattern: pattern)
}
/// @用戶
var atRanges: [NSRange]? {
let pattern = "@[\\u4e00-\\u9fa5a-zA-Z0-9_-]{2,30}"
return findRanges(pattern: pattern)
}
4. 設(shè)置屬性文本
找到相應(yīng)的range后就可以設(shè)置顏色、背景色等等屬性了
fileprivate func setupTextAttributes() {
textStorage.addAttributes([NSFontAttributeName: font,
NSForegroundColorAttributeName: textColor],
range: NSRange(location: 0, length: textStorage.length))
for range in urlRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
for range in topicRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
for range in atRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
}
5. 交互
- 要使
UILabel可交互前提是打開交互
isUserInteractionEnabled = true
- 點(diǎn)擊高亮部分
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
guard let location = touches.first?.location(in: self) else {
return
}
// 獲取點(diǎn)擊了第幾個字符
let index = layoutManager.glyphIndex(for: location, in: textContainer)
// 判斷index是否在 range里
for range in urlRanges ?? [] {
if NSLocationInRange(index, range) {
let str = (textStorage.string as NSString).substring(with: range)
print("點(diǎn)擊了\(str)鏈接")
return
}
}
for range in topicRanges ?? [] {
if NSLocationInRange(index, range) {
let str = (textStorage.string as NSString).substring(with: range)
print("點(diǎn)擊了\(str)話題")
return
}
}
for range in atRanges ?? [] {
if NSLocationInRange(index, range) {
let str = (textStorage.string as NSString).substring(with: range)
print("點(diǎn)擊了\(str)用戶"))
return
}
}
}
- 創(chuàng)建代理協(xié)議
當(dāng)點(diǎn)擊高亮文本后需要傳遞事件以及點(diǎn)擊的文本出去這時候可以利用代理協(xié)議。
protocol XXXLabelDelegate: NSObjectProtocol {
func labelDidSelectedLink(text: String)
func labelDidSelectedTopic(text: String)
func labelDidSelectedAt(text: String)
}
weak var delegate: XXXLabelDelegate?
6. 重寫屬性
當(dāng)在外部使用時，例如:
let label = XXXLabel()
label.frame = CGRect(x: 0, y: 0, width: 100, height: 30)
label.text = "@百度 https://www.baidu.com" // 或者 label.attributedText = “@百度 https://www.baidu.com”
label.font = UIFont.systemFont(ofSize: 15)
這時候label是沒有任何內(nèi)容的，因?yàn)橐呀?jīng)使用TextKit接管了UILabel，所以需要重寫屬性,給textStorage賦值然后再設(shè)置屬性文本即可
override var text: String? {
didSet {
prepareText()
}
}
override var attributedText: NSAttributedString? {
didSet {
prepareText()
}
}
override var font: UIFont! {
didSet {
prepareText()
}
}
override var textColor: UIColor! {
didSet {
prepareText()
}
}
fileprivate func prepareText() {
if let attributedText = attributedText {
textStorage.setAttributedString(attributedText)
}else if let text = text {
textStorage.setAttributedString(NSAttributedString(string: text))
}else {
textStorage.setAttributedString(NSAttributedString(string: ""))
return
}
// 設(shè)置Text屬性
setupTextAttributes()
}
fileprivate func setupTextAttributes() {
textStorage.addAttributes([NSFontAttributeName: font,
NSForegroundColorAttributeName: textColor],
range: NSRange(location: 0, length: textStorage.length))
for range in urlRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
for range in topicRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
for range in atRanges ?? [] {
textStorage.addAttributes([NSForegroundColorAttributeName: UIColor.blue], range: range)
}
}
GitHub
覺得不錯的給個star，非常感謝。
