粗体“<b>”标签和斜体“<i>”标签不适用于自定义字体系列

Bold `<b>` tag and Italic `<i>` tag not applied for custom font family

我在 html 字符串下方找到了 <b><i> 标签。

inputString = @"<b> Sample bold text </b> Normal Text <i> sample italic </i>";

下面的方法将return属性文本输入html字符串。

+(NSAttributedString *) returnRichTextForString:(NSString *) inputString {

  NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithData:[inputString dataUsingEncoding:NSUTF8StringEncoding]  options:@{   
        NSDocumentTypeDocumentAttribute:  NSHTMLTextDocumentType,
        NSCharacterEncodingDocumentAttribute: @(NSUTF8StringEncoding)
      }
  documentAttributes:nil
  error:nil];

   return attributedString;
}

然后自定义字体大小,family并传递给上面的方法。

NSString * strigAfterFontWrapper =  [NSString stringWithFormat:@"<style type='text/css'> body {font-size: %fpx}</style><font face='%@'>%@</font>", fontSize , customFontFamily, inputString];

label.numberOfLines = 0;

NSAttributedString *attributedstring = [NTUtilities returnRichTextForString:strigAfterFontWrapper];

label.attributedText = attributedstring;

但是,<b><i>没有应用在标签上!

It works fine with default system font! Any clue why it fails in the case of custom fonts ? What should I include to get bold or italic ?

您应该尝试使用系统字体,以排除您的自定义字体未正确添加到项目中的可能性。

我曾经遇到过同样的问题,但有标签。

This answer 帮我解决了。也许这对你有帮助。

编辑:

how to add custom fonts to iOS app

上找到了一篇非常好的文章

用我自己的 hack 解决了这个问题。在跳转到解决方案之前,我在 iOS 中阐明了新添加的自定义字体的效果。也就是说,如果该字体系列带有现成的粗体/斜体等属性,则会导致上述问题。如果没有,你将面临这样的问题。

解决方案:

+(NSAttributedString *) returnRichTextForString:(NSString *) inputString 方法中,添加以下行以覆盖现有的 NSAttributedString 属性。

[attributedString beginEditing];

[attributedString enumerateAttribute:NSParagraphStyleAttributeName inRange:NSMakeRange(0, attributedString.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {
    if (value) {
        NSMutableParagraphStyle *myStyle = (NSMutableParagraphStyle *)value;
        //Hack for bold effect to custom fonts
        if (myStyle.minimumLineHeight == 101) {
            [myStyle setMinimumLineHeight:0];
            [attributedString addAttribute:NSStrokeWidthAttributeName
                                     value:[NSNumber numberWithFloat:-3.0] range:range];
        }
        //Hack for italic/skew effect to custom fonts
        if (myStyle.minimumLineHeight == 99) {
            [myStyle setMinimumLineHeight:0];
            [attributedString addAttribute:NSObliquenessAttributeName
                                     value:[NSNumber numberWithFloat:0.30] range:range];
        }

    }
}];

[attributedString endEditing];

下面更新了 inputString

中的标记
<style type='text/css'> b { line-height:101px;} i {line-height:99px;} </style>

因此,在上行之后的最终标记,

inputString = @"<b> Sample bold text </b> Normal Text <i> sample italic </i><style type='text/css'> b { line-height:101px;} i {line-height:99px;} </style>";

这里,

Trick is to identify bold and italic tags based on line-height value in html and comparing it with minimumLineHeight attribute of paragraph style. i.e for example if line-height 101 then it will be bold and 99 then consider it as italic.

更新: 当 和 都应用于同一文本时,这会失败。为了克服这个问题,我在这里分享了稍微修改过的逻辑。保持相同的逻辑来识别斜体和粗体我在 NSAttributedstring 的结束编辑属性之前添加了以下行,

//Hack for bold effect.
[attributedString enumerateAttribute:NSStrikethroughStyleAttributeName inRange:NSMakeRange(0, attributedString.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {

    if (value) {

        [attributedString addAttribute:NSStrokeWidthAttributeName
                                                 value:[NSNumber numberWithFloat:-3.0] range:range];

        [attributedString addAttribute:NSStrikethroughStyleAttributeName
                                 value:[NSNumber numberWithFloat:0.0] range:range];
    }

}];

并在 html、

 b { text-decoration:line-through;}

我的完整方法如下:

  +(NSAttributedString *) returnRichTextForString:(NSString *) inputString {

  NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithData:[inputString dataUsingEncoding:NSUTF8StringEncoding]  options:@{
                                                                                                                                                                 NSDocumentTypeDocumentAttribute:  NSHTMLTextDocumentType,
                                                                                                                                                                 NSCharacterEncodingDocumentAttribute: @(NSUTF8StringEncoding)
                                                                                                                                                              }
                                                                           documentAttributes:nil
                                                                                        error:nil];


 [attributedString beginEditing];

   //Hack for italic/skew effect to custom fonts
 [attributedString enumerateAttribute:NSParagraphStyleAttributeName inRange:NSMakeRange(0, attributedString.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {

    if (value) {

        NSMutableParagraphStyle *myStyle = (NSMutableParagraphStyle *)value;

        if (myStyle.minimumLineHeight == 99) {
            [myStyle setMinimumLineHeight:0];
            [attributedString addAttribute:NSObliquenessAttributeName
                                     value:[NSNumber numberWithFloat:0.30] range:range];
        }

    }
}];

     //Hack for bold effect.
 [attributedString enumerateAttribute:NSStrikethroughStyleAttributeName inRange:NSMakeRange(0, attributedString.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {

     if (value) {

        [attributedString addAttribute:NSStrokeWidthAttributeName
                                                 value:[NSNumber numberWithFloat:-3.0] range:range];

        [attributedString addAttribute:NSStrikethroughStyleAttributeName
                                 value:[NSNumber numberWithFloat:0.0] range:range];
      }

}];


[attributedString endEditing];

return attributedString;
}