How to display Underlined Text in a Button on iOS?

Adding a screenshot for @Haider's answer.

Note: Only the text you highlight gets underlined, so you can underline just a specific range if you want.

I ended up underlining it in code anyway, just because I couldn't get Bold to work in conjunction with Underline for some reason. Could have been because of the font I was using, who knows.

@IBOutlet weak var underlineButton: UIButton! {
    didSet {
        let attrs = [
            NSFontAttributeName : UIFont(name: "MyCustomFont-Bold", size: 19.0)!,
            NSUnderlineStyleAttributeName: NSUnderlineStyle.StyleSingle.rawValue,
            NSForegroundColorAttributeName : UIColor.orangeColor()
        ]
        let attrString = NSMutableAttributedString(string: "Button text", attributes:attrs)
        underlineButton.setAttributedTitle(attrString, forState: .Normal)
    }
}

Swift 3.2

if let title = button.titleLabel?.text, title != "" {

    let attributeString = NSMutableAttributedString(string: title)

    attributeString.addAttribute(NSAttributedStringKey.underlineStyle, value: 1, range: NSMakeRange(0, title.count))

    button.titleLabel?.attributedText = attributeString
}

Objective C

NSString *tem = self.myButton.titleLabel.text;

if (tem != nil && ![tem isEqualToString:@""]) {
    NSMutableAttributedString *temString=[[NSMutableAttributedString alloc]initWithString:tem];
    [temString addAttribute:NSUnderlineStyleAttributeName
                      value:[NSNumber numberWithInt:1]
                      range:(NSRange){0,[temString length]}];

    self.myButton.titleLabel.attributedText = temString;
}

To do it in interface builder

1. Click on button/label
2. In Attributes inspector, change Title/Text to Attributed from plain
3. Select the text which you want to show.
4. Right click on it Goto Font->Underline