Xamarin iOS C＃下划线UIButton文本

另外，我发现它也能正常工作。谢谢！

        //Set attribute for underlineing information links
        var underlineAttr = new UIStringAttributes { UnderlineStyle = NSUnderlineStyle.Single, ForegroundColor = UIColor.White };

        //Privacy Button Link
        var PrivacyPolicy = new UIButton(new CGRect(10, s.MxHt - 40, (s.MxWd - 20) / 3, 30));
        PrivacyPolicy.BackgroundColor = UIColor.FromRGB(0, 92, 191);
        PrivacyPolicy.Font = UIFont.FromName("Roboto", 14f);            
        PrivacyPolicy.SetAttributedTitle(new NSAttributedString("Privacy Policy", underlineAttr), UIControlState.Normal);
        PrivacyPolicy.TouchUpInside += HandleBtnOpenPrivacyTouchUpInside;            
        if (iPad == false) { PrivacyPolicy.Font = UIFont.SystemFontOfSize(12); }            
        View.AddSubview(PrivacyPolicy);