How to implement the "return" of the desired version of the site?

Question

.NET

Good afternoon.
I have a small test site, mobile layout and desktop layout, but how to implement all this in net core?
So that the web api, for example, seeing the user agent of a mobile device, would give the layout for the mobile phone, and if the desktop gave the site assembly for the desktop.

Answer 1

It is a question of IIS as I understood.
Create an address rewriting rule in the conditions add {HTTP_user-agent} according to the pattern .*Mobile.* (all mobile agents must contain the word Mobile )

<rule name="test" enabled="false">
 <match url="(.*)" />  
  <conditions>
   <add input="{HTTP_user-agent}" pattern=".*Mobile.*" />
  </conditions>
  <action type="Redirect" url="/mobile.html" />
</rule>

Answer 2

Well, the logic for both versions will still be the same
1. Do everything based on CSS, the same bootstrap allows you to make a mobile version at the same time.
2. Since the business logic remains, we do this trick
https://docs.microsoft.com/ru-ru/dotnet/api/micros...

public class ViewLocationExpander: IViewLocationExpander {

    /// <summary>
    /// Used to specify the locations that the view engine should search to 
    /// locate views.
    /// </summary>
    /// <param name="context"></param>
    /// <param name="viewLocations"></param>
    /// <returns></returns>
    public IEnumerable<string> ExpandViewLocations(ViewLocationExpanderContext context, IEnumerable<string> viewLocations) {
        //{2} is area, {1} is controller,{0} is the action
        string[] locations = new string[] { "/Views/{2}/{1}/{0}.cshtml"};
        return locations.Union(viewLocations);          //Add mvc default locations after ours
    }


    public void PopulateValues(ViewLocationExpanderContext context) {
        context.Values["customviewlocation"] = nameof(ViewLocationExpander);
    }
}

services.Configure<RazorViewEngineOptions>(options => {
        options.ViewLocationExpanders.Add(new ViewLocationExpander());
    });

UPD: All the same, the results are cached, while working, well, option 2, writing your own RazorViewEngine
https://github.com/dotnet/aspnetcore/blob/main/src
... us to the mobile zone. but 2 times to write all controllers, plus you can make different versions.

Answer 3

Use Roman 's solution or define your own middle-ware, where the browser type will be determined.