试试UILabel上的分类:

下面是它的用法:

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

这是分类

UILabel h +及。

- (void) boldSubstring: (NSString*) substring;
- (void) boldRange: (NSRange) range;

UILabel + Boldify.m

- (void) boldRange: (NSRange) range {
    if (![self respondsToSelector:@selector(setAttributedText:)]) {
        return;
    }
    NSMutableAttributedString *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];
}

注意，这只适用于iOS 6及更高版本。在iOS 5或更早的版本中，它将被忽略。

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!

如果您希望更容易地使用带属性字符串，请尝试使用带属性字符串创建者，它将为您生成代码。https://itunes.apple.com/us/app/attributed-string-creator/id730928349

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”。

NSString *needToChangeStr=@"BOOK";
NSString *display_string=[NSString stringWithFormat:@"This is %@",book];

NSMutableAttributedString *attri_str=[[NSMutableAttributedString alloc]initWithString:display_string];

int begin=[display_string length]-[needToChangeStr length];
int end=[needToChangeStr length];


[attri_str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue-Bold" size:30] range:NSMakeRange(begin, end)];

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