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

这招对我很管用:

CGFloat boldTextFontSize = 17.0f;

myLabel.text = [NSString stringWithFormat:@"%@ 2012/10/14 %@",@"Updated:",@"21:59 PM"];

NSRange range1 = [myLabel.text rangeOfString:@"Updated:"];
NSRange range2 = [myLabel.text rangeOfString:@"21:59 PM"];

NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithString:myLabel.text];

[attributedText setAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:boldTextFontSize]}
                        range:range1];
[attributedText setAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:boldTextFontSize]}
                        range:range2];

myLabel.attributedText = attributedText;

对于Swift版本:见这里

AttributeString构造函数,把马克字符串,这样做可能意味着你的属性字符串没有其他属性,因此,如果您使用的是xib,你可以没有大胆的文本,将所有你想要的其他属性,然后通过属性在代码中列举范围你记下的字符串,并将它们应用于带属性字符串从你xib文件,然后重新申请你认为AttributeString特定领域。

检查TTTAttributedLabel。它是UILabel的一个替换，它允许你在一个标签中混合字体和颜色，通过设置NSAttributedString作为标签的文本。