在 iOS UILabel 上设置 BOLD 字体
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Setting BOLD font on iOS UILabel
提问by tech_human
I have assigned a custom font of 'Helvetica' with size 14 already for the text in UILabel using Interface Builder.
我已经使用界面生成器为 UILabel 中的文本分配了大小为 14 的“Helvetica”自定义字体。
I am using reusing the same label at multiple places, but at some place I have to display the text in bold.
我在多个地方重复使用相同的标签，但在某些地方我必须以粗体显示文本。
Is there any way I can just specify to make the existing font bold instead of creating the whole UIFont again? This is what I do now:
有什么方法可以指定使现有字体加粗而不是再次创建整个 UIFont 吗？这就是我现在所做的：
myLabel.font = [UIFont fontWithName:@"Helvetica Neue" size:14];
回答by Maksymilian Wojakowski
It's a fishy business to mess with the font names. And supposedly you have an italic font and you wanna make it bold - adding simply @"-Bold"to the name doesn't work. There's much more elegant way:
弄乱字体名称是一项可疑的业务。据说你有一个斜体字体，你想让它加粗 - 简单@"-Bold"地添加到名称中是行不通的。还有更优雅的方式：
- (UIFont *)boldFontWithFont:(UIFont *)font
{
UIFontDescriptor * fontD = [font.fontDescriptor
fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold];
return [UIFont fontWithDescriptor:fontD size:0];
}
size:0means 'keep the size as it is in the descriptor'.
You might find useful UIFontDescriptorTraitItalictrait if you need to get an italic font
size:0表示“保持描述符中的大小”。UIFontDescriptorTraitItalic如果您需要获得斜体字体，您可能会发现有用的特征
In Swift it would be nice to write a simple extension:
在 Swift 中编写一个简单的扩展会很好：
extension UIFont {
func withTraits(traits:UIFontDescriptorSymbolicTraits...) -> UIFont {
let descriptor = self.fontDescriptor().fontDescriptorWithSymbolicTraits(UIFontDescriptorSymbolicTraits(traits))
return UIFont(descriptor: descriptor, size: 0)
}
func bold() -> UIFont {
return withTraits(.TraitBold)
}
func italic() -> UIFont {
return withTraits(.TraitItalic)
}
func boldItalic() -> UIFont {
return withTraits(.TraitBold, .TraitItalic)
}
}
Then you may use it this way:
那么你可以这样使用它：
myLabel.font = myLabel.font.boldItalic()
myLabel.font = myLabel.font.bold()
myLabel.font = myLabel.font.withTraits(.TraitCondensed, .TraitBold, .TraitItalic)
回答by LE SANG
UPDATE:
Starting with iOS 8, messing with font names is no longer needed. Instead see newer answers that use UIFontDescriptorSymbolicTraits: hereand here.
更新：
从 iOS 8 开始，不再需要弄乱字体名称。而是查看使用UIFontDescriptorSymbolicTraits: here和here 的较新答案。
myLabel.font = [UIFont fontWithName:@"Helvetica-Bold" size:14];
If you wanna set it programmatically,you must check bold type is support or not in iOS, normally Bold or Italic will have format FontName-Bold, FontName-Italic, FontName-BoldItalic.
如果你想以编程方式设置它，你必须检查 iOS 是否支持粗体，通常粗体或斜体的格式为 FontName-Bold、FontName-Italic、FontName-BoldItalic。
Now, write a bold function
现在，写一个粗体函数
-(void)boldFontForLabel:(UILabel *)label{
UIFont *currentFont = label.font;
UIFont *newFont = [UIFont fontWithName:[NSString stringWithFormat:@"%@-Bold",currentFont.fontName] size:currentFont.pointSize];
label.font = newFont;
}
Then call it
然后调用它
[self boldFontForLabel:yourLabel];
回答by thatzprem
UIFont* boldFont = [UIFont boldSystemFontOfSize:[UIFont systemFontSize]];
[myLabel setFont:boldFont];
回答by cscott530
回答by Jasmeet
We just need the right font name. I find that iOSFonts.com is the most helpful resource for knowing exactly what name to use.
我们只需要正确的字体名称。我发现 iOSFonts.com 是准确了解要使用的名称的最有用的资源。
You can set Bold + ITALIC, by using FONT NAME "Arial-BoldItalicMT"
您可以使用字体名称“Arial-BoldItalicMT”设置粗体+斜体
It works in every Case:
它适用于每种情况：
[myLabel setFont:[UIFont fontWithName:@"Arial-BoldItalicMT" size:17]];
回答by RyanPliske
I did mine a little differently with Swift
我用Swift做的有点不同
var boldHelveticaFont = UIFont(name: "Helvetica Neue", size: 40)?.fontDescriptor().fontDescriptorWithSymbolicTraits(UIFontDescriptorSymbolicTraits.TraitBold)
self.InstructionsTextView.font = UIFont(descriptor: boldHelveticaFont!, size: 40)
回答by ingconti
for "swifters" give a try.
对于“快速者”，请尝试一下。
this sample controller will show 4 labels with all the variants.
此示例控制器将显示 4 个带有所有变体的标签。
import UIKit
class ViewController: UIViewController {
var labl: UILabel?
var labl2: UILabel?
var labl3: UILabel?
var labl4: UILabel?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let font = UIFont.systemFontOfSize(32)
labl = UILabel(frame: CGRectMake(20,20,400, 45))
labl!.text = "Attention:"
labl!.font = font
labl2 = UILabel(frame: CGRectMake(20,60,400, 45))
labl2!.text = "Attention:"
labl2!.font = bold(font)
labl3 = UILabel(frame: CGRectMake(20,100,400, 45))
labl3!.text = "Attention:"
labl3!.font = italic(font)
labl4 = UILabel(frame: CGRectMake(20,140,400, 45))
labl4!.text = "Attention:"
labl4!.font = boldAndItalic(font)
self.view.addSubview(labl!)
self.view.addSubview(labl2!)
self.view.addSubview(labl3!)
self.view.addSubview(labl4!)
}
// nice to write an extension...
func bold(font: UIFont) -> UIFont {
let descriptor = font.fontDescriptor().fontDescriptorWithSymbolicTraits([.TraitBold])
return UIFont(descriptor: descriptor, size: 0)
}
func boldAndItalic(font: UIFont) -> UIFont {
let descriptor = font.fontDescriptor().fontDescriptorWithSymbolicTraits([.TraitBold, .TraitItalic])
return UIFont(descriptor: descriptor, size: 0)
}
func italic(font: UIFont) -> UIFont {
let descriptor = font.fontDescriptor().fontDescriptorWithSymbolicTraits([.TraitItalic])
return UIFont(descriptor: descriptor, size: 0)
}
}
wulld be nice to write an extension for UIFont class.
为 UIFont 类编写扩展会很好。
回答by David West
You probably don't need an "extension" as such, if you want this for any custom fonts...
你可能不需要这样的“扩展”，如果你想要任何自定义字体......
Just add a function (similar to some above) that you can call from anywhere (i.e. without a class) and then you can embolden words within any string, on numerous occasions by calling just ONE LINEof code:
只需添加一个您可以从任何地方（即没有类）调用的函数（类似于上面的一些），然后您就可以在任何字符串中添加单词，在很多情况下只需调用一行代码：
To go in a file like constants.swift:
进入像constants.swift这样的文件：
import Foundation
import UIKit
func addBoldText(fullString: NSString, boldPartOfString: NSString, font: UIFont!, boldFont: UIFont!) -> NSAttributedString {
let nonBoldFontAttribute = [NSFontAttributeName:font!]
let boldFontAttribute = [NSFontAttributeName:boldFont]
let boldString = NSMutableAttributedString(string: fullString as String, attributes:nonBoldFontAttribute)
boldString.addAttributes(boldFontAttribute, range: fullString.rangeOfString(boldPartOfString as String))
return boldString
}
Then you can just call this one line of code for any UILabel:
然后你可以为任何 UILabel 调用这一行代码：
self.UILabel.attributedText = addBoldText("Check again in 30 DAYS to find more friends", boldPartOfString: "30 DAYS", font: normalFont!, boldFont: boldSearchFont!)
//Mark: Albeit that you've had to define these somewhere:
let normalFont = UIFont(name: "INSERT FONT NAME", size: 15)
let boldFont = UIFont(name: "INSERT BOLD FONT", size: 15)
回答by Kevin ABRIOUX
My contribution with an extension for UILabel updated for Swift 4 :
我为 Swift 4 更新了 UILabel 扩展的贡献：
extension UILabel{
func bold() -> UILabel {
if let descriptor = self.font.fontDescriptor.withSymbolicTraits(UIFontDescriptor.SymbolicTraits.traitBold){
self.font = UIFont(descriptor: descriptor, size: 0)
}
return self
}
}
Just call .bold() like that :
只需像这样调用 .bold() ：
let myLabel = UILabel()
myLabel.bold()
回答by user2643679
let boldHelveticaFont = UIFont(name: "HelveticaNeue", size: 25)?.fontDescriptor.withSymbolicTraits(UIFontDescriptor.SymbolicTraits.traitBold)
label.font = UIFont(descriptor: boldHelveticaFont!, size: 25)
