ASP.NET Core weird URL parsing. Single query string parameter

Question

I want to pass a string parameter to an action. Acreated a method in the HomeController with the following signature:

[HttpGet]
public IActionResult TestView([FromQuery] string test)
{
    return View(test);
}

This is my configuration class:

    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();
        }

        // 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();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }
            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }

When I go to https://localhost:5001/Home/TestView it works ok When I add a query string ?test=myvalue it fails to find the view. It tries to locate the view using weird paths.

    InvalidOperationException: The view 'myvalue' was not found. The following locations were searched:
    /Views/Home/myvalue.cshtml
    /Views/Shared/myvalue.cshtml

Is that a bug?

@Jacek I posted the whole Startup.cs. Though, I haven't touched it. It's from default MVC templete — Sergеу Isupov
– Sergеу Isupov, Commented Jan 25, 2021 at 12:35

tnk479 · Accepted Answer · 2021-01-25 12:46:21Z

2

The behavior is occurring because you passed the value "myvalue" as the first parameter of your returned ViewResult, which is the viewname parameter:

https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.viewresult.viewname?view=aspnetcore-5.0

If you change your return statement to:

return View();

Then you won't be passing a view name parameter and it will then search for a view named TestView.

answered Jan 25, 2021 at 12:46

tnk479

8142 gold badges13 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

tnk479 Over a year ago

No worries bro. If you were expecting to see "myvalue" in the browser, change your return type to string and then can return test, bypassing views altogether. Or you could instead bind the value to the view. Just depends what you want to do.

King King Over a year ago

@SergеуIsupov the first argument is the view name, if you want to pass something to the view, pass it to the second argument. So in your case, you can write View("TestView", test) - the view model then is of type string which should be aware of by the view to use it correctly.

Collectives™ on Stack Overflow

ASP.NET Core weird URL parsing. Single query string parameter

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related