How to Get User Browser Name ( User-Agent ) in ASP.NET Core

How to get user Browser name ( user-agent ) in Asp.net Core?

I think this was an easy one. Got the answer in Request.Headers["User-Agent"].ToString()

How to get browser information of client?

You can install Wangkanai.Detection package. The full documentation could be found here: https://github.com/wangkanai/Detection

Installation of detection library is now done with a single package
reference point.

PM> install-package Wangkanai.Detection -pre

While it is still possible to install the individual package if you just need that specific resolver.

PM> install-package Wangkanai.Detection.Device -pre  
PM> install-package Wangkanai.Detection.Browser -pre  
PM> install-package Wangkanai.Detection.Engine -pre   //concept
PM> install-package Wangkanai.Detection.Platform -pre //concept
PM> install-package Wangkanai.Detection.Crawler -pre  

Installation of Responsive library will bring in all dependency packages (This will include Wangkanai.Detection.Device).

PM> install-package Wangkanai.Responsive -pre

I think the following should be enough for you:

install-package Wangkanai.Detection -pre 
install-package Wangkanai.Detection.Browser -pre

Then you need to configure the Startup.cs by adding the detection service in the ConfigureServices method:

public void ConfigureServices(IServiceCollection services)
{
   // Add detection services container and device resolver service.
    services.AddDetection();
    services.AddDetectionCore().AddBrowser();
    // Add framework services.
    services.AddMvc();
}

And finally in your Controller, do something like this:

public class HomeController : Controller
{
    private readonly IDetection _detection;

    public HomeController(IDetection detection)
    {
        _detection = detection;
    }

    public IActionResult Index()
    {
        string browser_information = _detection.Browser.Type.ToString() +
                                     _detection.Browser.Version;
        //...
    }
} 

Trying to get the user-agent from request in asp.net web api self host

The absolutely simplest way to get the full user-agent from inside a WebAPI-controller is by doing this:

var userAgent = Request.Headers.UserAgent.ToString();

It gives exactly the same result as doing the manual step like this:

// var headers = request.Headers.GetValues("User-Agent");
// var userAgent = string.Join(" ", headers);

How to check user-agent in ASP.NET Core health check calls (MapHealthChecks)?

You can create a policy which performs user agent requirement validation

public class UserAgentRequirement : IAuthorizationRequirement
{
    public string UserAgent { get; }

    public UserAgentRequirement(string userAgent)
    {
        UserAgent = userAgent;
    }
}

public class UserAgentAuthorizationHandler : AuthorizationHandler<UserAgentRequirement>
{
    private readonly IHttpContextAccessor httpContextAccessor;

    public UserAgentAuthorizationHandler(IHttpContextAccessor httpContextAccessor)
    {
        this.httpContextAccessor = httpContextAccessor;
    }

    protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, UserAgentRequirement requirement)
    {
        var httpContext = httpContextAccessor.HttpContext;
        
        var agent = httpContext.Request.Headers["User-Agent"];
        if (agent == requirement.UserAgent)
        {
            context.Succeed(requirement);
        }
        else
        {
            context.Fail();
        }
        return Task.CompletedTask;
    }
}

Do not forget to register IHttpContextAccessor and UserAgentAuthorizationHandler. In Startup.cs

services.AddHttpContextAccessor();
services.AddScoped<IAuthorizationHandler, UserAgentAuthorizationHandler>();

services.AddAuthorization(options =>
{
    //...
    options.AddPolicy("HealthCheckPolicy", builder =>
    {
        builder.AddRequirements(new UserAgentRequirement("ReadyForRequest/1.0"));
    });
});

//...

app.UseEndpoints(endpoints =>
{
    endpoints
        .MapHealthChecks("/health", new HealthCheckOptions { AllowCachingResponses = false })
        .RequireAuthorization("HealthCheckPolicy");
    //...
});

---

Related Topics