Question

我正在尝试获取以html格式化的文本片段，以便在UITableViewCell中的iPhone上很好地显示。

到目前为止，我有这个：

NSError* error;
NSString* source = @"<strong>Nice</strong> try, Phil";
NSMutableAttributedString* str = [[NSMutableAttributedString alloc] initWithData:[source dataUsingEncoding:NSUTF8StringEncoding]
                                                           options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                                                     NSCharacterEncodingDocumentAttribute: [NSNumber numberWithInt:NSUTF8StringEncoding]}
                                                              documentAttributes:nil error:&error];

这种作品。我得到一些粗体'好'的文字！但是......它还将字体设置为Times Roman！这不是我想要的字体。我想我需要在documentAttributes中设置一些东西，但是，我找不到任何例子。

Answer 1

#import "UILabel+HTML.h"

@implementation UILabel (HTML)

- (void)jaq_setHTMLFromString:(NSString *)string {

    string = [string stringByAppendingString:[NSString stringWithFormat:@"<style>body{font-family: '%@'; font-size:%fpx;}</style>",
                                              self.font.fontName,
                                              self.font.pointSize]];
    self.attributedText = [[NSAttributedString alloc] initWithData:[string dataUsingEncoding:NSUnicodeStringEncoding]
                                                           options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                                                     NSCharacterEncodingDocumentAttribute: @(NSUTF8StringEncoding)}
                                                documentAttributes:nil
                                                             error:nil];
}


@end

这样您就不需要指定所需的字体，它将采用标签字体和大小。

Answer 2

Swift版本，基于Javier Querol

给出的答案

extension UILabel {
    func setHTMLFromString(text: String) {
        let modifiedFont = NSString(format:"<span style=\"font-family: \(self.font!.fontName); font-size: \(self.font!.pointSize)\">%@</span>", text) as String

        let attrStr = try! NSAttributedString(
            data: modifiedFont.dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true)!,
            options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: NSUTF8StringEncoding],
            documentAttributes: nil)

        self.attributedText = attrStr
    }
}

Swift 3.0和iOS 9 +

extension UILabel {
    func setHTMLFromString(htmlText: String) {
        let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)


        //process collection values
        let attrStr = try! NSAttributedString(
            data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
            options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue],
            documentAttributes: nil)


        self.attributedText = attrStr
    }
}

Answer 3

我实际上找到了解决这个问题的有效方法：

在解析之前更改HTML响应字符串中的字体。

NSString *aux = [NSString stringWithFormat:@"<span style=\"font-family: YOUR_FONT_NAME; font-size: SIZE\">%@</span>", htmlResponse];

示例：

NSString *aux = [NSString stringWithFormat:@"<span style=\"font-family: HelveticaNeue-Thin; font-size: 17\">%@</span>", [response objectForKey:@"content"]];

Swift版本：

let aux = "<span style=\"font-family: YOUR_FONT_NAME; font-size: SIZE\">\(htmlResponse)</span>"

Answer 4

想出来。一点熊，也许不是最好的答案。

此代码将完成所有字体更改。我知道它使用的是“Times New Roman”和“Times New Roman BoldMT”字体。但无论如何，这将找到粗体字体，让我重置它们。我也可以重置大小。

我真的希望/认为有一种方法可以在解析时设置它，但是如果有的话我找不到它。

    NSRange range = (NSRange){0,[str length]};
    [str enumerateAttribute:NSFontAttributeName inRange:range options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired usingBlock:^(id value, NSRange range, BOOL *stop) {
        UIFont* currentFont = value;
        UIFont *replacementFont = nil;

        if ([currentFont.fontName rangeOfString:@"bold" options:NSCaseInsensitiveSearch].location != NSNotFound) {
            replacementFont = [UIFont fontWithName:@"HelveticaNeue-CondensedBold" size:25.0f];
        } else {
            replacementFont = [UIFont fontWithName:@"HelveticaNeue-Thin" size:25.0f];
        }

        [str addAttribute:NSFontAttributeName value:replacementFont range:range];
    }];

Answer 5

更通用的方法是在枚举时查看字体特征，并创建具有相同特征的字体（粗体，斜体等）：

extension NSMutableAttributedString {

    /// Replaces the base font (typically Times) with the given font, while preserving traits like bold and italic
    func setBaseFont(baseFont: UIFont, preserveFontSizes: Bool = false) {
        let baseDescriptor = baseFont.fontDescriptor
        let wholeRange = NSRange(location: 0, length: length)
        beginEditing()
        enumerateAttribute(.font, in: wholeRange, options: []) { object, range, _ in
            guard let font = object as? UIFont else { return }
            // Instantiate a font with our base font's family, but with the current range's traits
            let traits = font.fontDescriptor.symbolicTraits
            guard let descriptor = baseDescriptor.withSymbolicTraits(traits) else { return }
            let newSize = preserveFontSizes ? descriptor.pointSize : baseDescriptor.pointSize
            let newFont = UIFont(descriptor: descriptor, size: newSize)
            self.removeAttribute(.font, range: range)
            self.addAttribute(.font, value: newFont, range: range)
        }
        endEditing()
    }
}

Answer 6

是的，有一个更简单的解决方案。在html源代码中设置字体！

NSError* error;
NSString* source = @"<strong>Nice</strong> try, Phil";
source = [source stringByAppendingString:@"<style>strong{font-family: 'Avenir-Roman';font-size: 14px;}</style>"];
NSMutableAttributedString* str = [[NSMutableAttributedString alloc] initWithData:[source dataUsingEncoding:NSUTF8StringEncoding]
                                                           options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                                                     NSCharacterEncodingDocumentAttribute: [NSNumber numberWithInt:NSUTF8StringEncoding]}
                                                              documentAttributes:nil error:&error];

希望这有帮助。

Answer 7

UILabel 扩展程序的Swift 4 + 更新

extension UILabel {
    func setHTMLFromString(text: String) {
        let modifiedFont = NSString(format:"<span style=\"font-family: \(self.font!.fontName); font-size: \(self.font!.pointSize)\">%@</span>" as NSString, text)

        let attrStr = try! NSAttributedString(
            data: modifiedFont.data(using: String.Encoding.unicode.rawValue, allowLossyConversion: true)!,
            options: [NSAttributedString.DocumentReadingOptionKey.documentType:NSAttributedString.DocumentType.html, NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue],
            documentAttributes: nil)

        self.attributedText = attrStr
    }
}

iOS 9 +

extension UILabel {
    func setHTMLFromString(htmlText: String) {
        let modifiedFont = NSString(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>" as NSString, htmlText) as String


        //process collection values
        let attrStr = try! NSAttributedString(
            data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
            options: [NSAttributedString.DocumentReadingOptionKey.documentType:NSAttributedString.DocumentType.html, NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue],
            documentAttributes: nil)


        self.attributedText = attrStr
    }
}

Answer 8

如果您在创建NSAttributedString的同时进行转换，则上述答案都可以正常工作。但我认为一个更好的解决方案，它适用于字符串本身，因此不需要访问输入，是以下类别：

extension NSMutableAttributedString
{
    func convertFontTo(font: UIFont)
    {
        var range = NSMakeRange(0, 0)

        while (NSMaxRange(range) < length)
        {
            let attributes = attributesAtIndex(NSMaxRange(range), effectiveRange: &range)
            if let oldFont = attributes[NSFontAttributeName]
            {
                let newFont = UIFont(descriptor: font.fontDescriptor().fontDescriptorWithSymbolicTraits(oldFont.fontDescriptor().symbolicTraits), size: font.pointSize)
                addAttribute(NSFontAttributeName, value: newFont, range: range)
            }
        }
    }
}

用作：

let desc = NSMutableAttributedString(attributedString: *someNSAttributedString*)
desc.convertFontTo(UIFont.systemFontOfSize(16))

适用于iOS 7 +

Answer 9

改进Victor的解决方案，包括颜色：

extension UILabel {
      func setHTMLFromString(text: String) {
          let modifiedFont = NSString(format:"<span style=\"color:\(self.textColor.toHexString());font-family: \(self.font!.fontName); font-size: \(self.font!.pointSize)\">%@</span>", text) as String

          let attrStr = try! NSAttributedString(
              data: modifiedFont.dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true)!,
              options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: NSUTF8StringEncoding],
              documentAttributes: nil)

          self.attributedText = attrStr
      }
  }

为此，您还需要使用uicolor转换为十六进制的YLColor.swift https://gist.github.com/yannickl/16f0ed38f0698d9a8ae7

Answer 10

使用NSHTMLTextDocumentType很慢且难以控制样式。我建议你试试我的图书馆，叫做Atributika。它有自己非常快的解析器。您还可以拥有任何标签名称并为其定义任何样式。

示例：

InternetTimeFromSystemTime

您可以在https://github.com/psharanda/Atributika

找到它

Answer 11

感谢您的回答，我真的很喜欢扩展，但我尚未转换为swift。对于那些仍然在Objective-C中的老学生来说，这应该有所帮助：D

-(void) setBaseFont:(UIFont*)font preserveSize:(BOOL) bPreserve {

UIFontDescriptor *baseDescriptor = font.fontDescriptor;

[self enumerateAttribute:NSFontAttributeName inRange:NSMakeRange(0, [self length]) options:0 usingBlock:^(id  _Nullable value, NSRange range, BOOL * _Nonnull stop) {

    UIFont *font = (UIFont*)value;
    UIFontDescriptorSymbolicTraits traits = font.fontDescriptor.symbolicTraits;
    UIFontDescriptor *descriptor = [baseDescriptor fontDescriptorWithSymbolicTraits:traits];
    UIFont *newFont = [UIFont fontWithDescriptor:descriptor size:bPreserve?baseDescriptor.pointSize:descriptor.pointSize];

    [self removeAttribute:NSFontAttributeName range:range];
    [self addAttribute:NSFontAttributeName value:newFont range:range];

}];    }

快乐的编码！ --Greg Frame

Answer 12

Swift 5 用于UILabel和UITextView的解决方案

extension UITextView {
func setHTMLFromString(htmlText: String) {
    let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)

    let attrStr = try! NSAttributedString(
        data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
        options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding:String.Encoding.utf8.rawValue],
        documentAttributes: nil)

    self.attributedText = attrStr
}

}

extension UILabel {
func setHTMLFromString(htmlText: String) {
    let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)

    let attrStr = try! NSAttributedString(
        data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
        options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding:String.Encoding.utf8.rawValue],
        documentAttributes: nil)

    self.attributedText = attrStr
}

}

UILabel的用法

self.label.setHTMLFromString(htmlText: htmlString)

UITextView的用法

self.textView.setHTMLFromString(htmlText: htmlString)

输出

Answer 13

Swift 3 字符串扩展名，包括nil字体。没有字体的属性取自其他SO问题，不记得哪一个：（

extension String {
    var html2AttributedString: NSAttributedString? {
        guard let data = data(using: .utf8) else {
            return nil
        }

        do {
            return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue], documentAttributes: nil)
        }
        catch {
            print(error.localizedDescription)
            return nil
        }
    }

    public func getHtml2AttributedString(font: UIFont?) -> NSAttributedString? {
        guard let font = font else {
            return html2AttributedString
        }

        let modifiedString = "<style>body{font-family: '\(font.fontName)'; font-size:\(font.pointSize)px;}</style>\(self)";

        guard let data = modifiedString.data(using: .utf8) else {
            return nil
        }

        do {
            return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue], documentAttributes: nil)
        }
        catch {
            print(error)
            return nil
        }
    }
}

Answer 14

快速解决方案

以下方法有效。您可以使用这种方法很好地提供字体系列，字体大小和颜色。随时提出更改建议或任何更好的方法。

extension UILabel {

func setHTMLFromString(htmlText: String,fontFamily:String,fontColor:String) {
    let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', \(fontFamily); font-size: \(self.font!.pointSize); color: \(fontColor) ; \">%@</span>", htmlText)
    do{
        if let valData = modifiedFont.data(using: .utf8){
            let attrStr = try NSAttributedString(data: valData, options: [NSAttributedString.DocumentReadingOptionKey.documentType : NSAttributedString.DocumentType.html.rawValue], documentAttributes: nil)
            self.attributedText = attrStr
        }
    }
    catch{
        print("Conversion failed with \(error)")
        self.attributedText = nil
        }
    }
}

Answer 15

将每个人的答案结合在一起，我进行了两个扩展，可以使用html文本设置标签。上面的某些答案不能正确解释属性字符串中的字体系列。其他人不能满足我的需求，或者以其他方式失败。让我知道您是否有需要改进的地方。

我希望这对某人有帮助。

extension UILabel {
    /// Sets the label using the supplied html, using the label's font and font size as a basis.
    /// For predictable results, using only simple html without style sheets.
    /// See https://stackoverflow.com/questions/19921972/parsing-html-into-nsattributedtext-how-to-set-font
    ///
    /// - Returns: Whether the text could be converted.
    @discardableResult func setAttributedText(fromHtml html: String) -> Bool {
        guard let data = html.data(using: .utf8, allowLossyConversion: true) else {
            print(">>> Could not create UTF8 formatted data from \(html)")
            return false
        }

        do {
            let mutableText = try NSMutableAttributedString(
                data: data,
                options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html, NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue],
                documentAttributes: nil)
            mutableText.replaceFonts(with: font)
            self.attributedText = mutableText
            return true
        } catch (let error) {
            print(">>> Could not create attributed text from \(html)\nError: \(error)")
            return false
        }
    }
}

extension NSMutableAttributedString {

    /// Replace any font with the specified font (including its pointSize) while still keeping
    /// all other attributes like bold, italics, spacing, etc.
    /// See https://stackoverflow.com/questions/19921972/parsing-html-into-nsattributedtext-how-to-set-font
    func replaceFonts(with font: UIFont) {
        let baseFontDescriptor = font.fontDescriptor
        var changes = [NSRange: UIFont]()
        enumerateAttribute(.font, in: NSMakeRange(0, length), options: []) { foundFont, range, _ in
            if let htmlTraits = (foundFont as? UIFont)?.fontDescriptor.symbolicTraits,
                let adjustedDescriptor = baseFontDescriptor.withSymbolicTraits(htmlTraits) {
                let newFont = UIFont(descriptor: adjustedDescriptor, size: font.pointSize)
                changes[range] = newFont
            }
        }
        changes.forEach { range, newFont in
            removeAttribute(.font, range: range)
            addAttribute(.font, value: newFont, range: range)
        }
    }
}

Answer 16

这是NSString的扩展，它使用Objective-C返回NSAttributedString。

它可以正确处理带有HTML标签的字符串，并设置所需的字体和字体颜色，同时保留HTML标签，包括BOLD，ITALICS ...

最重要的是，它不依赖任何HTML标记来设置字体属性。

@implementation NSString (AUIViewFactory)

- (NSAttributedString*)attributedStringFromHtmlUsingFont:(UIFont*)font fontColor:(UIColor*)fontColor
{
    NSMutableAttributedString* mutableAttributedString = [[[NSAttributedString alloc] initWithData:[self dataUsingEncoding:NSUTF8StringEncoding] options:@{NSDocumentTypeDocumentAttribute : NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute : @(NSUTF8StringEncoding)} documentAttributes:nil error:nil] mutableCopy]; // parse text with html tags into a mutable attributed string
    [mutableAttributedString beginEditing];
    // html tags cause font ranges to be created, for example "This text is <b>bold</b> now." creates three font ranges: "This text is " , "bold" , " now."
    [mutableAttributedString enumerateAttribute:NSFontAttributeName inRange:NSMakeRange(0, mutableAttributedString.length) options:0 usingBlock:^(id value, NSRange range, BOOL* stop)
    { // iterate every font range, change every font to new font but preserve symbolic traits such as bold and italic (underline and strikethorugh are preserved automatically), set font color
        if (value)
        {
            UIFont* oldFont = (UIFont*)value;
            UIFontDescriptor* fontDescriptor = [font.fontDescriptor fontDescriptorWithSymbolicTraits:oldFont.fontDescriptor.symbolicTraits];
            UIFont* newFont = [UIFont fontWithDescriptor:fontDescriptor size:font.pointSize];
            [mutableAttributedString removeAttribute:NSFontAttributeName range:range]; // remove the old font attribute from this range
            [mutableAttributedString addAttribute:NSFontAttributeName value:newFont range:range]; // add the new font attribute to this range
            [mutableAttributedString addAttribute:NSForegroundColorAttributeName value:fontColor range:range]; // set the font color for this range
        }
    }];
    [mutableAttributedString endEditing];
    return mutableAttributedString;
}

@end

Answer 17

实际上，存在一种更简单，更清洁的方式。只需在解析HTML后设置字体：

 NSMutableAttributedString *text = [[NSMutableAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
                                                                     options:@{
                                                                               NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                                                               NSCharacterEncodingDocumentAttribute: @(NSUTF8StringEncoding)}
                                                          documentAttributes:nil error:nil];
    [text addAttributes:@{NSFontAttributeName: [UIFont fontWithName:@"Lato-Regular" size:20]} range:NSMakeRange(0, text.length)];

将HTML解析为NSAttributedText - 如何设置字体？

17 个答案: