Swift3/Swift4 转换Html为纯文本

Swift 3或者Swift 4 添加String扩展，把Html字符串转换为纯文本

Xcode 9 beta • Swift 4

extension String {
    var html2AttributedString: NSAttributedString? {
        do {
            return try NSAttributedString(data: Data(utf8),
                          options: [.documentType: NSAttributedString.DocumentType.html,
                                    .characterEncoding: String.Encoding.utf8.rawValue],
                          documentAttributes: nil)
        } catch {
            print("error:", error)
            return  nil
        }
    }
    var html2String: String {
        return html2AttributedString?.string ?? ""
    }
}

Xcode 8.3 • Swift 3.1

extension String {
    var html2AttributedString: NSAttributedString? {
        do {
            return try NSAttributedString(data: Data(utf8), 
                          options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                    NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue],
                          documentAttributes: nil)
        } catch {
            print("error:", error)
            return nil
        }
    }
    var html2String: String {
        return html2AttributedString?.string ?? ""
    }
}

使用方法

str.html2String