Swift

Question

我有一个 textView，允许用户输入 NSAttributedString，转换成 html 字符串，然后存储到数据库中。我还有将 html 字符串转换回并显示在 textView 中进行编辑的代码。我的转换码是

extension String {
    func htmlAttributedString() -> NSAttributedString? {
        guard let data = self.data(using: String.Encoding.utf16, allowLossyConversion: false) else { return nil }
        guard let html = try? NSMutableAttributedString(
            data: data,
            options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
            documentAttributes: nil) else { return nil }
        return html
    }
}

extension NSAttributedString {
    func htmlString() -> String? {
        let documentAttributes = [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType]
        do {
            let htmlData = try self.data(from: NSMakeRange(0, self.length), documentAttributes:documentAttributes)
            if let htmlString = String(data:htmlData, encoding:String.Encoding.utf8) { return htmlString }
        }
        catch {}
        return nil
    }
}

但是问题是每次保存和显示字符串时，所有字体都会变大。例如，我有一个 html 字符串

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv="Content-Style-Type" content="text/css">
<title></title>
<meta name="Generator" content="Cocoa HTML Writer">
<style type="text/css">
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 17.0px '.SF UI Text'; color: #000000}
span.s1 {font-family: '.SFUIText'; font-weight: normal; font-style: normal; font-size: 17.00pt}
</style>
</head>
<body>
<p class="p1"><span class="s1">text</span></p>
</body>
</html>

在我将其转换为 NSAttributedString 并再次转换回来之后，其他一切都相同，但 css 行更改为此。

<style type="text/css">
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; line-height: 28.0px; font: 22.7px '.SF UI Text'; color: #000000; -webkit-text-stroke: #000000}
span.s1 {font-family: '.SFUIText'; font-weight: normal; font-style: normal; font-size: 22.67pt; font-kerning: none}
</style>

我错过了什么吗？感谢任何帮助！

Answer 1

试试这个我从一些帮助中找到的方法，然后转换为 Swift 3:

func newAttrSize(blockQuote: NSAttributedString) -> NSAttributedString
{
    let yourAttrStr = NSMutableAttributedString(attributedString: blockQuote)
    yourAttrStr.enumerateAttribute(.font, in: NSMakeRange(0, yourAttrStr.length), options: .init(rawValue: 0)) {
        (value, range, stop) in
        if let font = value as? UIFont {
            let resizedFont = font.withSize(font.pointSize * 0.75)
            yourAttrStr.addAttribute(.font, value: resizedFont, range: range)
        }
    }

    return yourAttrStr
}

Answer 2

我遇到了同样的问题，简单的解决方法是您只转换为 RTF 格式而不是 HTML。效果很好。

Swift - 将 html 字符串转换为属性字符串并再次返回时，字体大小会增加

Swift - Font size increases when converting html string to attributed string and back again

uitextview

nsattributedstring

ios