iOS开发-UILabel和UIButton添加下划线

关于UILabel和UIButton有的时候需要添加下划线，一般有两种方式通过默认的NSMutableAttributedString设置，第二种就是在drawRect中画一条下划线，本文就简单的选择第一种，第二种有兴趣的可以自己研究一下。

UILabel设置下划线:

    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 100, 310, 50)];

    label.backgroundColor = [UIColor redColor];

    [label setLineBreakMode:NSLineBreakByWordWrapping];

    label.numberOfLines =3;

    [label setFont:[UIFont systemFontOfSize:14]];

    NSMutableAttributedString *content = [[NSMutableAttributedString alloc]initWithString:[NSString stringWithFormat:@"博文地址:http://www.cnblogs.com/xiaofeixiang 博客园-FlyElephant QQ群:228407086"]];

    NSRange contentRange = {0,[content length]};

    [content addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:contentRange];

    

    label.attributedText = content;

    [self.view addSubview:label];

UIButton设置下划线:

  UIButton *button=[[UIButton alloc]initWithFrame:CGRectMake(10, 200, 80, 30)];

    NSMutableAttributedString *title = [[NSMutableAttributedString alloc] initWithString:@"FlyElephant"];

    NSRange titleRange = {0,[title length]};

    [title addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:titleRange];

    [button setAttributedTitle:title

                      forState:UIControlStateNormal];

    [button setBackgroundColor:[UIColor redColor]];

    [button.titleLabel setFont:[UIFont systemFontOfSize:14]];

    [self.view addSubview:button];

最终效果如下: