UITextView – 无法在文本上设置下划线或删除线属性？
每当我尝试在UITextView的attributedText上设置下划线或删除线属性时，我都会遇到运行时故障。 其他属性，如字体和背景颜色没有问题。 这是一段代码片段。 我所拥有的只是一个带有单个UITextView的测试项目。 我在iOS 11上。
class ViewController: UIViewController { @IBOutlet weak var myTextView: UITextView! var myMutableString = NSMutableAttributedString(string: "") override func viewDidLoad() { super.viewDidLoad() let string = "The cow jumped over the moon" as NSString myMutableString = NSMutableAttributedString(string: string as String) let underlineAttribute = [NSAttributedStringKey.underlineStyle: NSUnderlineStyle.styleSingle] myMutableString.addAttributes(underlineAttribute, range: string.range(of: "cow")) myTextView.attributedText = myMutableString } } 这导致文本消失并打印出一些错误：
2017-11-05 19:43:34.708830-0800 UITextView_Test[11771:907014] -[_SwiftValue _getValue:forType:]: unrecognized selector sent to instance 0x60c00004eb50 2017-11-05 19:43:34.709351-0800 UITextView_Test[11771:907014] : Exception -[_SwiftValue _getValue:forType:]: unrecognized selector sent to instance 0x60c00004eb50 raised during typesetting layout manager 1 containers, text backing has 28 characters Currently holding 28 glyphs. Glyph tree contents: 28 characters, 28 glyphs, 1 nodes, 64 node bytes, 64 storage bytes, 128 total bytes, 4.57 bytes per character, 4.57 bytes per glyph Layout tree contents: 28 characters, 28 glyphs, 0 laid glyphs, 0 laid line fragments, 1 nodes, 64 node bytes, 0 storage bytes, 64 total bytes, 2.29 bytes per character, 2.29 bytes per glyph, 0.00 laid glyphs per laid line fragment, 0.00 bytes per laid line fragment , glyph range {0 28}. Ignoring... 2017-11-05 19:43:34.709827-0800 UITextView_Test[11771:907014] -[_SwiftValue _getValue:forType:]: unrecognized selector sent to instance 0x60c00004eb50 2017-11-05 19:43:34.710014-0800 UITextView_Test[11771:907014] : Exception -[_SwiftValue _getValue:forType:]: unrecognized selector sent to instance 0x60c00004eb50 raised during typesetting layout manager 1 containers, text backing has 28 characters Currently holding 28 glyphs. Glyph tree contents: 28 characters, 28 glyphs, 1 nodes, 64 node bytes, 64 storage bytes, 128 total bytes, 4.57 bytes per character, 4.57 bytes per glyph Layout tree contents: 28 characters, 28 glyphs, 0 laid glyphs, 0 laid line fragments, 1 nodes, 64 node bytes, 0 storage bytes, 64 total bytes, 2.29 bytes per character, 2.29 bytes per glyph, 0.00 laid glyphs per laid line fragment, 0.00 bytes per laid line fragment , glyph range {0 28}. Ignoring...
您的下划线样式无效。 改变这一行：
let underlineAttribute = [NSAttributedStringKey.underlineStyle: NSUnderlineStyle.styleSingle]
对此：
let underlineAttribute = [NSAttributedStringKey.underlineStyle: NSUnderlineStyle.styleSingle.rawValue]
结果：
