这在Interface Builder中很容易做到:

1)在属性检查器中设置UILabel为Attributes

2)选择你想加粗的部分短语

3)在字体选择器中更改其字体(或相同字体的粗体)

这是所有!

在这种情况下，你可以尝试，

UILabel *displayLabel = [[UILabel alloc] initWithFrame:/*label frame*/];
displayLabel.font = [UIFont boldSystemFontOfSize:/*bold font size*/];

NSMutableAttributedString *notifyingStr = [[NSMutableAttributedString alloc] initWithString:@"Updated: 2012/10/14 21:59 PM"];
[notifyingStr beginEditing];
[notifyingStr addAttribute:NSFontAttributeName
                     value:[UIFont systemFontOfSize:/*normal font size*/]
                     range:NSMakeRange(8,10)/*range of normal string, e.g. 2012/10/14*/];
[notifyingStr endEditing];

displayLabel.attributedText = notifyingStr; // or [displayLabel setAttributedText: notifyingStr];

斯威夫特4:

// attribute with color red and Bold
var attrs1 = [NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 20), NSAttributedStringKey.foregroundColor: UIColor.red]

// attribute with color black and Non Bold
var attrs2 = [NSAttributedStringKey.font: UIFont(name: "Roboto-Regular", size: 20), NSAttributedStringKey.foregroundColor: UIColor.black]  

var color1 = NSAttributedString(string: "RED", attributes: attrs1)

var color2 = NSAttributedString(string: " BLACK", attributes: attrs2)

var string = NSMutableAttributedString()

string.append(color1)

string.append(color2)

// print the text with **RED** BLACK
print("Final String : \(string)")

我刚刚在我的项目中实现的以下代码不需要NSRange(在Swift中):

//Code sets label (yourLabel)'s text to "Tap and hold(BOLD) button to start recording."
let boldAttribute = [
  //You can add as many attributes as you want here.
  NSFontAttributeName: UIFont(name: "HelveticaNeue-Bold", size: 18.0)!
]
        
let regularAttribute = [NSFontAttributeName: UIFont(name: "HelveticaNeue-Light", size: 18.0)!]
        
let beginningAttributedString = NSAttributedString(string: "Tap and ", attributes: regularAttribute )
let boldAttributedString = NSAttributedString(string: "hold ", attributes: boldAttribute)
let endAttributedString = NSAttributedString(string: "button to start recording.", attributes: regularAttribute )
let fullString =  NSMutableAttributedString()
        
fullString.appendAttributedString(beginningAttributedString)
fullString.appendAttributedString(boldAttributedString)
fullString.appendAttributedString(endAttributedString)

yourLabel.attributedText = fullString

在UILabel中使文本加粗并加下划线。只需在代码中添加以下行。

NSRange range1 = [lblTermsAndCondition.text rangeOfString:NSLocalizedString(@"bold_terms", @"")];
NSRange range2 = [lblTermsAndCondition.text rangeOfString:NSLocalizedString(@"bold_policy", @"")];
NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithString:lblTermsAndCondition.text];
[attributedText setAttributes:@{NSFontAttributeName:[UIFont fontWithName:fontBold size:12.0]}
                        range:range1];
[attributedText setAttributes:@{NSFontAttributeName:[UIFont fontWithName:fontBold size:12.0]}
                        range:range2];


[attributedText addAttribute:(NSString*)kCTUnderlineStyleAttributeName
                  value:[NSNumber numberWithInt:kCTUnderlineStyleSingle]
                  range:range1];

[attributedText addAttribute:(NSString*)kCTUnderlineStyleAttributeName
                       value:[NSNumber numberWithInt:kCTUnderlineStyleSingle]
                       range:range2];



lblTermsAndCondition.attributedText = attributedText;

这是基于bbrame的category的category。它的工作原理类似，但允许您在累积结果中多次加粗相同的UILabel。

UILabel h +及。

@interface UILabel (Boldify)
- (void) boldSubstring: (NSString*) substring;
- (void) boldRange: (NSRange) range;
@end

UILabel + Boldify.m

@implementation UILabel (Boldify)
- (void)boldRange:(NSRange)range {
    if (![self respondsToSelector:@selector(setAttributedText:)]) {
        return;
    }
    NSMutableAttributedString *attributedText;
    if (!self.attributedText) {
        attributedText = [[NSMutableAttributedString alloc] initWithString:self.text];
    } else {
        attributedText = [[NSMutableAttributedString alloc] initWithAttributedString:self.attributedText];
    }
    [attributedText setAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:self.font.pointSize]} range:range];
    self.attributedText = attributedText;
}

- (void)boldSubstring:(NSString*)substring {
    NSRange range = [self.text rangeOfString:substring];
    [self boldRange:range];
}
@end

有了这个修正，你可以多次使用它，例如:

myLabel.text = @"Updated: 2012/10/14 21:59 PM";
[myLabel boldSubstring: @"Updated:"];
[myLabel boldSubstring: @"21:59 PM"];

将会得到:“更新日期:2012/10/14 21:59 PM”。