如何获取 UIFont 实例的字体大小?
或者,如果有人可以为 UIFont 实现这个方法?
- (UIFont *)boldFont;
这是一个旧答案,它不再是最佳解决方案,请改为查看已接受的答案。
-(UIFont *)boldFont{
//First get the name of the font (unnecessary, but used for clarity)
NSString *fontName = self.fontName;
//Some fonts having -Regular on their names. so we have to remove that before append -Bold / -BoldMT
fontName = [[fontName componentsSeparatedByString:@"-"] firstObject];
//Then append "-Bold" to it.
NSString *boldFontName = [fontName stringByAppendingString:@"-Bold"];
//Then see if it returns a valid font
UIFont *boldFont = [UIFont fontWithName:boldFontName size:self.pointSize];
//If it's valid, return it
if(boldFont) return boldFont;
//Seems like in some cases, you have to append "-BoldMT"
boldFontName = [fontName stringByAppendingString:@"-BoldMT"];
boldFont = [UIFont fontWithName:boldFontName size:self.pointSize];
//Here you can check if it was successful, if it wasn't, then you can throw an exception or something.
return boldFont;
}
要从 UIFont 实例访问字体大小,请使用
@property(nonatomic, readonly) CGFloat pointSize
还有更多属性可以告诉字体大小(对于大写,小等......)
capHeight,xHeight,pointSize
使用下面来访问粗体字体
UIFont* myboldFont = [UIFont boldSystemFontOfSize:11];
UIFontDescriptor
是非常强大的类,可用于获取所需字体的粗体版本。它应该是完全安全且面向未来的,因为它只需要使用公共 API 并且不依赖于任何字符串修改。
这是 Swift 3 中的代码:
extension UIFont {
func bold() -> UIFont? {
let fontDescriptorSymbolicTraits: UIFontDescriptorSymbolicTraits = [fontDescriptor.symbolicTraits, .traitBold]
let bondFontDescriptor = fontDescriptor.withSymbolicTraits(fontDescriptorSymbolicTraits)
return bondFontDescriptor.flatMap { UIFont(descriptor: $0, size: pointSize) }
}
}
这是objective-c中的代码:
@implementation UIFont (RABoldFont)
- (UIFont *)ra_boldFont
{
UIFontDescriptor *fontDescriptor = [self fontDescriptor];
UIFontDescriptorSymbolicTraits traits = fontDescriptor.symbolicTraits;
traits = traits | UIFontDescriptorTraitBold;
UIFontDescriptor *boldFontDescriptor = [fontDescriptor fontDescriptorWithSymbolicTraits:traits];
return [UIFont fontWithDescriptor:boldFontDescriptor size:self.pointSize];
}
@end
这是查找字体大小的最简单方法
UIFont *anyFont;
//initialization and other stuff here
现在在某个时候你想找到它的大小
CGFloat fontSize= [anyFont pointSize];
使用NSString+UIKit方法来测量具有特定字体的字符串的大小。
iPhone 将同名的普通字体和粗体字体视为完全独立的字体,因此没有简单的方法可以在它们之间进行转换。例如,操作系统认为 ArialMT 和 Arial-BoldMT 是完全不同的字体。
编辑:我可能误解了你的问题。也许您正在寻找UIFont 的pointSize属性?
您可以使用 Core Text 检查粗体。使用kCTFontBoldTrait
.
Swift 3 版本的rafał-augustyniak 答案
extension UIFont {
func boldFont() -> UIFont? {
let fontDescriptor = self.fontDescriptor
let fontDescriptorSymbolicTraits: UIFontDescriptorSymbolicTraits = [ fontDescriptor.symbolicTraits, .traitBold ]
guard let boldFontDesc = fontDescriptor.withSymbolicTraits(fontDescriptorSymbolicTraits) else {
return nil
}
return UIFont(descriptor: boldFontDesc, size: pointSize)
}
}