如何在 Swift 中创建 ruby​​ 文本？

问题描述

我正在尝试添加 ruby​​ 文本注释，以便我可以在日语应用程序中的汉字词上方显示假名。我相信 CTRubyAnnotationCreateWithAttributes 是用于创建 ruby​​ 文本的函数，但是当我运行这个简单的应用程序时，它只显示主要文本。有人可以指出我缺少什么吗？谢谢。

import UIKit

class ViewController: UIViewController {

  @IBOutlet var textView: UITextView!
  
  override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    let word = "食べ物"
    let ruby = "たべもの"
    
    var text = furigana(main: word,furigana: ruby)
    textView.attributedText = text
  }

  func furigana(main: String,furigana: String) -> NSMutableAttributedString {
    
    var ruby = furigana
    var unmanage = Unmanaged.passRetained(ruby as CFString)
    defer { unmanage.release() }
    var text: [Unmanaged<CFString>?] = [unmanage,.none,.none]
    
    let rubyAttribute: [AnyHashable: Any] = [
        kCTRubyAnnotationSizefactorAttributeName: 0.5,kCTForegroundColorAttributeName: UIColor.black
    ]
    
    let annotation = CTRubyAnnotationCreateWithAttributes(.auto,.auto,.before,ruby as CFString,rubyAttribute as CFDictionary)
    
    //let annotation = CTRubyAnnotationCreate(.center,0.5,&text)
    
    let attributed = NSMutableAttributedString(
      string: main,attributes: [kCTRubyAnnotationAttributeName as NSAttributedString.Key: annotation])
    
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.lineHeightMultiple = 1.0
    paragraphStyle.linespacing = 12
    
    attributed.addAttribute(NSAttributedString.Key.paragraphStyle,value: paragraphStyle,range: NSMakeRange(0,attributed.length))
    attributed.addAttributes([NSAttributedString.Key.font: UIFont(name: "HiraMinProN-W3",size: 14.0)!,NSAttributedString.Key.verticalGlyphForm: false,],(attributed.length)))
    
    return attributed
  }
}

解决方法

我能够通过两项更改使其正常工作：

1. 使用 UILabel 而不是 UITextView。
2. 删除 verticalGlyphForm 属性。

我没有看到任何明显的文档，但似乎 UITextView 可能不支持 ruby​​ 文本。至于verticalGlyphForm，the documentation says it's not supported on iOS and if specified the behavior is undefined。