ios - 使用 +[UIFont preferredFontForTextStyle :xxx]? 时如何有选择地将文本设为斜体

Question

我像这样创建一个 NSMutableAttributedString:

UIFont *font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
NSDictionary *attributes = @{ NSFontAttributeName: font };
NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:str attributes:attributes];

现在我想斜体化 attrStr 的特定范围，例如:

- (void)setAttributes:(NSDictionary *)attrs range:(NSRange)range;

但由于我从未要求过特定字体，所以我不确定该如何处理。

Answer 1

// Create the normal body style font    
UIFont *font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];

// Get the font's descriptor and add the italics trait
UIFontDescriptor *fontDesc = [font fontDescriptor];
fontDesc = [fontDesc fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitItalic];

// Create the italicized font from the descriptor
UIFont *italicsFont = [UIFont fontWithDescriptor:fontDesc size:font.pointSize];

// Create the attributes dictionary that we'll use to italicize parts of our NSMutableAttributedString
NSDictionary *italicsAttributes = @{ NSFontAttributeName: italicsFont };