1.给UILabel 添加下划线

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 100, 300, 100)];  label.backgroundColor = [UIColor redColor];  label.numberOfLines = 3;  NSMutableAttributedString *content = [[NSMutableAttributedString alloc]initWithString:[NSString stringWithFormat:@"您的待办业务条fasdfasdfosadfjasdkljfklasjklfjasdlkjfklasdjklfjalskdjflkadsj"]];  NSRange contentRange = {
   0,[content length]};  [content addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:contentRange];  label.attributedText = content;  [self.view addSubview:label];

2. http://blog.csdn.net/chaoyuan899/article/details/38306141

方法一：

 

[objc] 

NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:@"查看所有中奖记录"];
NSRange strRange = {       0,[str length]};
[str addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:strRange];
[_awardDisplayBtn setAttributedTitle:str forState:UIControlStateNormal];

 

方法二：

 

HyperlinksButton.h

 

#import <UIKit/UIKit.h>

@interface HyperlinksButton : UIButton
{
    UIColor *lineColor;
}
-(void)setColor:(UIColor*)color;
@end

 

HyperlinksButton.m 

 

#import "HyperlinksButton.h"

@implementation HyperlinksButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

    }
    return self;
}

-(void)setColor:(UIColor *)color{
    lineColor = [color copy];
    [self setNeedsDisplay];
}


- (void) drawRect:(CGRect)rect {
    CGRect textRect = self.titleLabel.frame;
    CGContextRef contextRef = UIGraphicsGetCurrentContext();

    CGFloat descender = self.titleLabel.font.descender;
    if([lineColor isKindOfClass:[UIColor class]]){
        CGContextSetStrokeColorWithColor(contextRef, lineColor.CGColor);
    }

    CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + textRect.size.height + descender+1);
    CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender+1);

    CGContextClosePath(contextRef);
    CGContextDrawPath(contextRef, kCGPathStroke);
}
@end

直接将这个类 copy 到工程中，，然后将需要加下划线的 Button 类名改为 HyperlinksButton就可以了，提供了 setColor: 这个接口，可以设置下划线颜色，代码很简单，不解释了。UILabel 同理可得。

 

示例结果：

代码在。