Request.Browser.IsMobileDevice equivalent in ASP.Net Core (2.0)

Question

In legacy asp.net and asp.net MVC, we could easily check if the request is from mobile device by using IsMobileDevice property of the request (System.Web.HttpContext.Current.Request.Browser.IsMobileDevice) but in asp.net core due to huge structural and architectural changes in Request class (Microsoft.AspNetCore.Http.Request), this property (Browser.IsMobileDevice) doesn't exist anymore. Is there any official equivalent from Microsoft for .NetCore to addres this issue (I mean utility method or something)??.

Do note that I can easily write a method that does this by checking user agent property of Request class like below but It's not completely reliable because due to variety of user agents and updating and adding new user agents I can't grantee that my regex variables cover all the possible user agents and moreover I would have to update them (regex variables values) from time to time to keep them up-to-date.

Here is my code, but I don't wanna use it, it's not good practice though. I'm looking for a better alternative

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 BrowserIsMobile(Request request)
{
    var u = request.Headers["HTTP_USER_AGENT"].ToString();

    if (u.Length < 4)
        return false;

    if (MobileCheck.IsMatch(u) || MobileVersionCheck.IsMatch(u.Substring(0, 4)))
        return true;
    return false;
}

You should use such switches anymore and instead create responsive UIs (in pure html/css/javascript) which dynamically change the layout of your website based on the device size. See https://en.wikipedia.org/wiki/Responsive_web_design — Tseng, Apr 14 '18 at 17:14
As per https://stackoverflow.com/questions/1829089/how-does-ismobiledevice-work IsMobile uses the same technique. — Pawel, Apr 14 '18 at 18:47
@Pawel your link is for .net not .netcore. I have no issue .net but this property doesn't exist any more in .net core — Code_Worm, Apr 14 '18 at 19:19
I am saying that .Net is also parsing user agent with regexes to return this information. — Pawel, Apr 14 '18 at 19:24
@Pawel yes, of course because there is no other way to do so.But it's not that simple as I read your link's first answer microsoft also check *.browser files which are inside .net directory — Code_Worm, Apr 14 '18 at 21:03
@Pawel even if it's just a simple regex check I'd rather not do it myself because if I use a build in .net core functionality instead first It's widely used and more reliable (than doing it myself) and second I don't need to worry about updating my regex values to support new user agents. — Code_Worm, Apr 14 '18 at 21:05
@Tseng you have to use the switches if your mobile site is Amp. — prospector, May 17 '18 at 06:52
Best solution I've found: stackoverflow.com/a/71053664/7204020 Works like a charm in asp.net core. — Sylwia M, Mar 17 '22 at 14:00

score 5 · Answer 1 · answered Aug 03 '21 at 19:27

it can be achieved by creating a class that injects HttpContext and contain a method that read "User-Agent" and apply the same regular expression to detect is mobile browser or not

public class MyUtility
{
    HttpContext httpContext;
    public MyUtility(HttpContext _httpContext)
    {
        httpContext = _httpContext;
    }

    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);
    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 bool IsMobileDeviceBrowser()
    {
        var u = httpContext.Request.Headers["User-Agent"].ToString();
        bool IsMobileBrowser = false;
        if (u.Length > 4 && (MobileCheck.IsMatch(u) || MobileVersionCheck.IsMatch(u.Substring(0, 4))))
            IsMobileBrowser = true;
        return IsMobileBrowser;
    }
}

then you can consume inside any controller or startup class as below

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseRouting();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapGet("/", async httpContext =>
            {
               if(new MyUtility(httpContext).IsMobileDeviceBrowser())
                await httpContext.Response.WriteAsync("Is Mobile Browser ");
                else
                await httpContext.Response.WriteAsync("Is Desktop Browser ");
            });
        });
    }
}

Hi @Code_Worm is this answer your question I tried on sample core application and work fine with me — MHassan, Aug 03 '21 at 19:28

Request.Browser.IsMobileDevice equivalent in ASP.Net Core (2.0)

1 Answers1

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