public class UAParserUserAgent
{
    private readonly static uap.Parser s_uap;
    private static readonly Regex s_pdfConverterPattern = new Regex(@"wkhtmltopdf", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
    # region Mobile UAs, OS & Devices
    private static readonly HashSet<string> s_MobileOS = new HashSet<string>
    {
      "Android",
      "iOS",
      "Windows Mobile",
      "Windows Phone",
      "Windows CE",
      "Symbian OS",
      "BlackBerry OS",
      "BlackBerry Tablet OS",
      "Firefox OS",
      "Brew MP",
      "webOS",
      "Bada",
      "Kindle",
      "Maemo"
    };
    private static readonly HashSet<string> s_MobileBrowsers = new HashSet<string>
    {
      "Android",
      "Firefox Mobile",
      "Opera Mobile",
      "Opera Mini",
      "Mobile Safari",
      "Amazon Silk",
      "webOS Browser",
      "MicroB",
      "Ovi Browser",
      "NetFront",
      "NetFront NX",
      "Chrome Mobile",
      "Chrome Mobile iOS",
      "UC Browser",
      "Tizen Browser",
      "Baidu Explorer",
      "QQ Browser Mini",
      "QQ Browser Mobile",
      "IE Mobile",
      "Polaris",
      "ONE Browser",
      "iBrowser Mini",
      "Nokia Services (WAP) Browser",
      "Nokia Browser",
      "Nokia OSS Browser",
      "BlackBerry WebKit",
      "BlackBerry", "Palm",
      "Palm Blazer",
      "Palm Pre",
      "Teleca Browser",
      "SEMC-Browser",
      "PlayStation Portable",
      "Nokia",
      "Maemo Browser",
      "Obigo",
      "Bolt",
      "Iris",
      "UP.Browser",
      "Minimo",
      "Bunjaloo",
      "Jasmine",
      "Dolfin",
      "Polaris",
      "Skyfire"
    };
    private static readonly HashSet<string> s_MobileDevices = new HashSet<string>
    {
      "BlackBerry",
      "MI PAD",
      "iPhone",
      "iPad",
      "iPod",
      "Kindle",
      "Kindle Fire",
      "Nokia",
      "Lumia",
      "Palm",
      "DoCoMo",
      "HP TouchPad",
      "Xoom",
      "Motorola",
      "Generic Feature Phone",
      "Generic Smartphone"
    };
    #endregion
    private readonly HttpContextBase _httpContext;
    private string _rawValue;
    private UserAgentInfo _userAgent;
    private DeviceInfo _device;
    private OSInfo _os;
    private bool? _isBot;
    private bool? _isMobileDevice;
    private bool? _isTablet;
    private bool? _isPdfConverter;
    static UAParserUserAgent()
    {
      s_uap = uap.Parser.GetDefault();
    }
    public UAParserUserAgent(HttpContextBase httpContext)
    {
      this._httpContext = httpContext;
    }
    public string RawValue
    {
      get
      {
        if (_rawValue == null)
        {
          if (_httpContext.Request != null)
          {
            _rawValue = _httpContext.Request.UserAgent.ToString();
          }
          else
          {
            _rawValue = "";
          }
        }
        return _rawValue;
      }
      // for (unit) test purpose
      set
      {
        _rawValue = value;
        _userAgent = null;
        _device = null;
        _os = null;
        _isBot = null;
        _isMobileDevice = null;
        _isTablet = null;
        _isPdfConverter = null;
      }
    }
    public virtual UserAgentInfo UserAgent
    {
      get
      {
        if (_userAgent == null)
        {
          var tmp = s_uap.ParseUserAgent(this.RawValue);
          _userAgent = new UserAgentInfo(tmp.Family, tmp.Major, tmp.Minor, tmp.Patch);
        }
        return _userAgent;
      }
    }
    public virtual DeviceInfo Device
    {
      get
      {
        if (_device == null)
        {
          var tmp = s_uap.ParseDevice(this.RawValue);
          _device = new DeviceInfo(tmp.Family, tmp.IsSpider);
        }
        return _device;
      }
    }
    public virtual OSInfo OS
    {
      get
      {
        if (_os == null)
        {
          var tmp = s_uap.ParseOS(this.RawValue);
          _os = new OSInfo(tmp.Family, tmp.Major, tmp.Minor, tmp.Patch, tmp.PatchMinor);
        }
        return _os;
      }
    }
    public virtual bool IsBot
    {
      get
      {
        if (!_isBot.HasValue)
        {
          _isBot = _httpContext.Request.Browser.Crawler || this.Device.IsBot;
        }
        return _isBot.Value;
      }
    }
    public virtual bool IsMobileDevice
    {
      get
      {
        if (!_isMobileDevice.HasValue)
        {
          _isMobileDevice =
            s_MobileOS.Contains(this.OS.Family) ||
            s_MobileBrowsers.Contains(this.UserAgent.Family) ||
            s_MobileDevices.Contains(this.Device.Family);
        }
        return _isMobileDevice.Value;
      }
    }
    public virtual bool IsTablet
    {
      get
      {
        if (!_isTablet.HasValue)
        {
          _isTablet =
            Regex.IsMatch(this.Device.Family, "iPad|Kindle Fire|Nexus 10|Xoom|Transformer|MI PAD|IdeaTab", RegexOptions.CultureInvariant) ||
            this.OS.Family == "BlackBerry Tablet OS";
        }
        return _isTablet.Value;
      }
    }
    public virtual bool IsPdfConverter
    {
      get
      {
        if (!_isPdfConverter.HasValue)
        {
          _isPdfConverter = s_pdfConverterPattern.IsMatch(this.RawValue);
        }
        return _isPdfConverter.Value;
      }
    }
}
public sealed class DeviceInfo
{
    public DeviceInfo(string family, bool isBot)
    {
      this.Family = family;
      this.IsBot = isBot;
    }
    public override string ToString()
    {
      return this.Family;
    }
    public string Family { get; private set; }
    public bool IsBot { get; private set; }
}
public sealed class OSInfo
{
    public OSInfo(string family, string major, string minor, string patch, string patchMinor)
    {
      this.Family = family;
      this.Major = major;
      this.Minor = minor;
      this.Patch = patch;
      this.PatchMinor = patchMinor;
    }
    public override string ToString()
    {
      var str = VersionString.Format(Major, Minor, Patch, PatchMinor);
      return (this.Family + (!string.IsNullOrEmpty(str) ? (" " + str) : null));
    }
    public string Family { get; private set; }
    public string Major { get; private set; }
    public string Minor { get; private set; }
    public string Patch { get; private set; }
    public string PatchMinor { get; private set; }
    private static string FormatVersionString(params string[] parts)
    {
      return string.Join(".", (from v in parts
                   where !string.IsNullOrEmpty(v)
                   select v).ToArray<string>());
    }
}
public sealed class UserAgentInfo
{
    public UserAgentInfo(string family, string major, string minor, string patch)
    {
      this.Family = family;
      this.Major = major;
      this.Minor = minor;
      this.Patch = patch;
    }
    public override string ToString()
    {
      var str = VersionString.Format(Major, Minor, Patch);
      return (this.Family + (!string.IsNullOrEmpty(str) ? (" " + str) : null));
    }
    public string Family { get; private set; }
    public string Major { get; private set; }
    public string Minor { get; private set; }
    public string Patch { get; private set; }
}
internal static class VersionString
{
    public static string Format(params string[] parts)
    {
      return string.Join(".", (from v in parts
                   where !string.IsNullOrEmpty(v)
                   select v).ToArray<string>());
    }
}

UAParserUserAgent userAgent = new UAParserUserAgent(this.HttpContext);
dto.OSInfo = userAgent.OS.ToString();
dto.Device = userAgent.Device.ToString() != "Other" ? userAgent.Device.ToString() : "電腦";
dto.Agent = userAgent.UserAgent.ToString();
dto.RawValue = userAgent.RawValue.ToString();
//if (userAgent.IsMobileDevice)
//{
//  Debug.WriteLine("這是一個手機(jī)");
//  ViewBag.MobilePc = "手機(jī)";
//}
//else if (userAgent.IsTablet)
//{
//  ViewBag.MobilePc = "平板";
//  Debug.WriteLine("這是一個平板");
//}
//else
//{
//  ViewBag.MobilePc = "普通電腦";
//  Debug.WriteLine("這是一個普通電腦");
//}