Question

我想将HTML Tag转换为String，我使用enum根据我需要执行某些操作的长度来查找String的内容长度。

我的modal课程，

class PostViewModel {
    var content: TextContent
    enum TextContent {
            case expanded(String)
            case collapsed(String)

            static func == (lhs: TextContent, rhs: TextContent) -> Bool {
                switch lhs {
                case .collapsed(let content):
                    if case collapsed(content) = rhs {
                        return true
                    }
                    return false
                case .expanded(let content):
                    if case expanded(content) = rhs {
                        return true
                    }
                    return false
                }
            }
        }
    }

我在cellForItem(at index: Int)，

中调用此功能

func applyVerticalSizeConcernedRendering(fromViewModel viewModel: PostViewModel) {
    switch viewModel.content {
        case .collapsed(let content):
            let str = content.html2String
            print(str)
        case .expanded(let content):
            break
    }
}

html2String extension等级为String

extension String {
      var html2AttributedString: NSMutableAttributedString? {
      guard let data = data(using: String.Encoding.utf8) else { return nil }
            let attrs: [String: Any] = [
                NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue
            ]
            do {
                let attrStr = try NSMutableAttributedString(data: data, options: attrs, documentAttributes: nil)
                return attrStr
            } catch let error as NSError {
                print(error.localizedDescription)
                return  nil
            }
        }
        var html2String: String {
            return html2AttributedString?.string ?? ""
        }
    }

问题是将HTML标记转换为String

时崩溃了

它在这里崩溃，

let attrStr = try NSMutableAttributedString(data: data, options: attrs, documentAttributes: nil)

String不为空

以下是示例HTML String，

<strong>I want to test HTML Tags<br><\/strong>dsfhjdjf sjdfdj  djfjdfj djkf dfjdhf <strong>adjf<br>asks <\/strong>djfdkf<br><strong>dfdjk dkfjdk <\/strong>dfjik iai <strong>adsfhj<\/strong>

当我尝试使用硬编码值时，此功能正常，但只有当我从String

获取enum时它才会崩溃

崩溃日志是，

*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array'

有人可以帮忙吗？

Answer 1

试试这个，不需要做你已完成的整个过程：

extension String {
    var htmlAttributedString: 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 htmlString: String {
        return htmlAttributedString?.string ?? ""

}

<强>用法：

let html = "<strong>I want to test HTML Tags<br></strong>dsfhjdjf sjdfdj  djfjdfj djkf dfjdhf <strong>adjf<br>asks</strong>djfdkf<br><strong>dfdjk dkfjdk </strong>dfjik iai <strong>adsfhj</strong>"
let str = html.htmlString

所以你基本上只是在你的字符串上使用String extension。这是我在项目中使用的

<强>更新
以上内容如下：

Here是您可以尝试的示例项目。

将HTML标记转换为字符串

1 个答案: