swift4 - swift4 迁移后 DocumentReadingOptionKey 键损坏

Question

使用以下代码从 swift3 迁移到 swift4，

let options: [NSAttributedString.DocumentReadingOptionKey: AnyHashable] =
                          [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue]

            let str = try NSAttributedString( data:string!.data(using: String.Encoding.utf8, allowLossyConversion: true
                )!, options:options, documentAttributes: nil)

iOS 9+没有问题，运行iOS 8.3时，控制台输出:"dyld: Symbol not found: _NSCharacterEncodingDocumentOption";它将在注释“.characterEncoding: String.Encoding.utf8.rawValue”后传递。

Answer 1

我找到了解决方案。您应该为 swift4 删除 .characterEncoding。
它适用于 ios8,9,11。

例子:

public func htmlToString() -> String? {
        guard let data = data(using: .utf8) else { return nil }
        do {
            return try NSAttributedString(
                data: data,
                options: [
                    .documentType: NSAttributedString.DocumentType.html
                ],
                documentAttributes: nil
            ).string
        } catch let error as NSError {
            print(error.localizedDescription)
            return  nil
        }
    }

祝你有美好的一天!