Mobile Device Detection in asp.net

Question

The following is a Mobile device detection code which encompasses three different conditions

if (Request.Browser.IsMobileDevice) {    //Do Something } else if (((System.Web.Configuration.HttpCapabilitiesBase)myBrowserCaps).IsMobileDevice) {   //Do Something } else if (IsMobileDevice(mobileDevices)) {   //Do Something }  public bool IsMobileDevice() {      private static string[] mobileDevices = new string[] {"iphone","ppc"                                                    "windows ce","blackberry",                                                    "opera mini","mobile","palm"                                                    "portable","opera mobi" };           string userAgent = Request.UserAgent.ToString().ToLower();          return mobileDevices.Any(x => userAgent.Contains(x));  } 

I was forced to write three conditions as they were failing for some devices.

Can anyone suggest a better approach?

Answer 1

taking and change a bit the code from : http://detectmobilebrowsers.com/

public static class Utils {         // update : 5/April/2018     static Regex MobileCheck = new Regex(@"(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.Compiled);     static Regex MobileVersionCheck = new Regex(@"1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.Compiled);      public static bool fBrowserIsMobile()     {         Debug.Assert(HttpContext.Current != null);          if (HttpContext.Current.Request != null && HttpContext.Current.Request.ServerVariables["HTTP_USER_AGENT"] != null)         {             var u = HttpContext.Current.Request.ServerVariables["HTTP_USER_AGENT"].ToString();              if (u.Length < 4)                 return false;              if (MobileCheck.IsMatch(u) || MobileVersionCheck.IsMatch(u.Substring(0, 4)))                 return true;         }          return false;     } } 

and this is how you call it.

if (Utils.fBrowserIsMobile()) {     // go to mobile pages } 

What I have change to the code from http://detectmobilebrowsers.com/

• Make static compile the Regex for faster check.
• Fix a bug in the case that u is less than 4 characters.
• Other checks.

Using Cache

This code is fast, and the one trick is that we have made static and pre compile the regex. How ever i suggest after the first check to save the result on user session and use that session variable that is a lot faster.