Get User Browser name/user-agent In Asp.net Core

I'm working on an ASP.NET Core application where I need to store the user agent in my database for every time a client makes a request to our system. I'm using .NET Core 6, so  in this post, we'll discuss how to retrieve the user's browser name (user-agent) basicaly device type in .NET Core.

To retrieve the user's browser name (user-agent) in an ASP.NET Core application, we can utilize the IHttpContextAccessor service along with the Request.Headers collection. 

First, ensure that you have registered IHttpContextAccessor in the ConfigureServices method of your Startup class:

    services.AddHttpContextAccessor();
  

Then, within your controller or service where you need to access the user-agent, inject the IHttpContextAccessor service:

    private readonly IHttpContextAccessor _httpContextAccessor;

    public MyService(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }
  

Now, you can retrieve the user-agent from the Request.Headers collection:

    public string GetUserBrowserName()
    {
        var userAgent = _httpContextAccessor.HttpContext.Request.Headers["User-Agent"].ToString();
        return userAgent;
    }
  

If you're using .NET>= 6 , there's a convenient property you can use to retrieve the user-agent string. In a controller, you can access it like this:

    var userAgent = HttpContext.Request.Headers.UserAgent;
  

If you're not within a controller, you can inject an implementation of IHttpContextAccessor and access it as follows:

    using Microsoft.AspNetCore.Http;

    public class UserProifle
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public UserProifle(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor;
        }

        public string? GetUserAgent()
        {
            return _httpContextAccessor?.HttpContext?.Request.Headers.UserAgent;
        }
    }
  

Please note that you'll need to register IHttpContextAccessor by adding the following line of code in your program.cs or startup.cs based on your .net version.

    services.AddHttpContextAccessor();
  

3

If you are using Web API then in a Web API, we can access the user-agent header from the incoming HTTP request. We'll utilize the `HttpContext` to retrieve this information.

First, let's create a controller where we'll retrieve the user-agent:

// UserController.cs
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("[controller]")]
public class UserController : ControllerBase
{
    [HttpGet("user-agent")]
    public IActionResult GetUserAgent()
    {
        string userAgent = Request.Headers["User-Agent"];
        return Ok(userAgent);
    }
}

In UserController , we define a GET endpoint `/user-agent` which returns the user-agent string when a client makes a GET request to this endpoint, the `GetUserAgent` method is called, and we retrieve the user-agent header from the request.

GET request to `/user-agent`, you'll receive the user-agent string in the response body and but remember to handle cases where the user-agent may be missing or malformed.