基本完成, 个别极端情况待测试.

Author: lixiang1994

AttributedString.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
 s.name         = "AttributedString"
-s.version      = "1.6.2"
+s.version      = "1.6.3"
 s.summary      = "基于Swift字符串插值快速构建你想要的富文本, 支持点击按住等事件获取, 支持多种类型过滤"
 
 s.homepage     = "https://github.com/lixiang1994/AttributedString"

Sources/Extension/UIKit/UILabel/UILabelExtension.swift

@@ -333,15 +333,17 @@ fileprivate extension UILabel {
         guard let attributedString = AttributedString(text) else { return nil }
 
         // 构建同步Label设置的TextKit
-        let textStorage = NSTextStorage(attributedString: attributedString.value)
+        let textStorage = NSTextStorage()
         let textContainer = NSTextContainer(size: .init(bounds.size.width, bounds.size.height))
         let layoutManager = NSLayoutManager()
-        layoutManager.delegate = UILabelLayoutManagerDelegate.shared // 重新计算行高确保TextKit与UILabel显示一致
+        layoutManager.delegate = UILabelLayoutManagerDelegate.shared // 重新计算行高确保TextKit与UILabel显示同步
         textContainer.lineBreakMode = lineBreakMode
         textContainer.lineFragmentPadding = 0.0
         textContainer.maximumNumberOfLines = numberOfLines
+        layoutManager.usesFontLeading = false   // UILabel没有使用FontLeading排版
         layoutManager.addTextContainer(textContainer)
         textStorage.addLayoutManager(layoutManager)
+        textStorage.setAttributedString(attributedString.value) // 放在最后添加富文本 TextKit的坑
 
         // 确保布局
         layoutManager.ensureLayout(for: textContainer)

Sources/Extension/UIKit/UILabel/UILabelLayoutManagerDelegate.swift

@@ -57,8 +57,10 @@ class UILabelLayoutManagerDelegate: NSObject, NSLayoutManagerDelegate {
 
         var rect = lineFragmentRect.pointee
         var used = lineFragmentUsedRect.pointee
-        used.size.height = max(maximum.lineHeight, used.height)
-        rect.size.height = used.height + maximum.lineSpacing + paragraphSpacing + paragraphSpacingBefore
+        // 以最大的高度为准 (可解决附件问题), 同时根据最大行数是否为1来判断rect和used是否需要一致, 以解决1行数多余的行间距问题.
+        let temp = max(maximum.lineHeight, used.height)
+        rect.size.height = temp + maximum.lineSpacing + paragraphSpacing + paragraphSpacingBefore
+        used.size.height = textContainer.maximumNumberOfLines == 1 ? temp : rect.height
 
         // 重新赋值最终结果
         lineFragmentRect.pointee = rect
@@ -98,8 +100,7 @@ extension UILabelLayoutManagerDelegate {
         var paragraph: NSParagraphStyle?
         textStorage.enumerateAttributes(in: characterRange, options: .longestEffectiveRangeNotRequired) {
             (attributes, range, stop) in
-            // 实际计算使用的是 NSOriginalFont lineHeight.
-            print(attributes[.originalFont])
+            // 使用 NSOriginalFont 的行高进行计算 https://juejin.im/post/6844903838252531725
             guard let font = (attributes[.originalFont] ?? attributes[.font]) as? UIFont else { return }
             paragraph = paragraph ?? attributes[.paragraphStyle] as? NSParagraphStyle
 
@@ -148,6 +149,7 @@ extension UILabelLayoutManagerDelegate {
 
 extension NSAttributedString.Key {
 
+    /// 参考: https://juejin.im/post/6844903838252531725
     static let originalFont: NSAttributedString.Key = .init("NSOriginalFont")
 }