核心代码
[attributedString addAttributes:@{NSFontAttributeName:appFont(14 * rectScale(), NO),NSParagraphStyleAttributeName:style} range:NSMakeRange(0, attributedString.length)];

    NSString *content = shareInfo[@"content"] ?: @"";
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithData:[content dataUsingEncoding:NSUnicodeStringEncoding] options:@{ NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType } documentAttributes:nil error:nil];
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    style.minimumLineHeight = 25 * rectScale();
    style.maximumLineHeight = 25 * rectScale();
    [attributedString addAttributes:@{NSFontAttributeName:appFont(14 * rectScale(), NO),NSParagraphStyleAttributeName:style} range:NSMakeRange(0, attributedString.length)];

注意，这种写法会将html的富文本样式只改成一种字体
，如果原来的字体有多种，修改过之后之后一种font

修改前

修改后