How to apply both bold and italic font to an NSAttributedString?

问题

I'm trying to parse my own HTML string into an NSAttributedString for rendering in a UITextView.

So, for when the string appears as such:

<strong><em>This should be both bold and italic</strong></em>

I want to apply a distinct bold and italic font to the eventual NSAttributedString, so that if the user ever removes either the bold or italic font from it during editing, one of the remaining fonts will stay intact.

This is the main reason why I don't simply want to apply a single font style like bold-italic, as other SO answers have suggested.

回答1:

Here is my answer after looking through different sources:

UIFontDescriptor *fontDescriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleBody];

UIFontDescriptor *changedFontDescriptor;      
NSDictionary *attributes;

uint32_t existingTraitsWithNewTrait = [fontDescriptor symbolicTraits] | UIFontDescriptorTraitBold | UIFontDescriptorTraitItalic;
changedFontDescriptor = [fontDescriptor fontDescriptorWithSymbolicTraits:existingTraitsWithNewTrait];

UIFont *updatedFont = [UIFont fontWithDescriptor:changedFontDescriptor size:0.0];

attributes = @{ NSFontAttributeName : updatedFont };

attributedString = [[NSAttributedString alloc] initWithString:yourString attributes:attributes];

来源：https://stackoverflow.com/questions/26023027/how-to-apply-both-bold-and-italic-font-to-an-nsattributedstring