UILabel和UIButton添加下划線

關於UILabel和UIButton有的時候需要添加下划線，一般有兩種方式通過默認的 NSMutableAttributedString設置，第二種就是在drawRect中畫一條下划線，本文就簡單的選擇第一種，第二種有興趣的可以自己研究一下。

UILabel設置下划線:

  

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 博客園-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];</pre><br>

UIButton設置下划線:

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];